JP2000040914A - Antenna device - Google Patents

Abstract

(57) [Problem] To provide a small-sized antenna device capable of receiving radio waves from a plurality of extremely close satellites with high sensitivity and obtaining a practical antenna gain. SOLUTION: Waveguides 140a and 140b are arranged corresponding to respective collection positions of radio waves transmitted from two satellites and collected by a reflector. Waveguides 140a, 14
0b, the dielectric rod 142
a, 142b are fitted. Dielectric rods 142a, 142b
, The center-to-center distance between the waveguides 140a and 140b is set to an optimum value corresponding to the distance between two satellites, and the diameters of the waveguides 140a and 140b are formed so small that they do not overlap. Even so, the directivity of the primary radiator 14 can be optimized. As a result, spillover does not occur, and problems such as a decrease in antenna gain and a decrease in satellite radio reception C / N ratio due to an increase in reception noise do not occur.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an antenna device for receiving radio waves in satellite communication and satellite broadcasting, and more particularly to an antenna device for receiving radio waves from a plurality of satellites in close proximity.

[0002]

2. Description of the Related Art In recent years, broadcasting satellites (BSs)
llite), satellite broadcasting such as broadcasting using a communication satellite (CS), or satellite communication using a communication satellite. Spreading. In order to receive radio waves in such satellite broadcasting or satellite communication,
For example, an antenna device including a parabolic reflector and a receiving unit arranged near the focal point of the reflector is generally used. Here, the receiving unit is
Normally, a primary radiator, also called a feed horn, serving as a waveguide for guiding the radio waves collected by the reflector to a receiving circuit section described later, and converts the radio waves guided by the feed horn into an electric signal (received signal). At the same time, the received signal is subjected to predetermined processing (frequency conversion, amplification, etc.) and output, and the
And a receiving circuit unit for supplying to a tuner and the like.

FIG. 20 shows a simplified structure of such a feed horn. (A) of this figure shows a side cross section of the feed horn, and (b) shows a state viewed from the front (the side of a not-shown reflector). This feed horn is used for a so-called single beam antenna for receiving a radio wave from one satellite, and has a funnel-shaped opening 101 extending toward a reflector (not shown), and an integral part of the opening 101. Formed cylindrical waveguide 10
And 2. The feed horn is arranged so that the center of the opening 101 substantially coincides with the focal point F of a not-shown reflecting mirror. The radio wave reflected by the reflecting mirror and collected at the focal point F propagates inside the waveguide 102, and is converted into a radio wave / electric signal in a receiving circuit unit (not shown) disposed behind (upper side in the figure). Part. Although not shown, a cap (protective lid) called a radome is provided in the opening 101 of the feed horn in order to prevent intrusion of rainwater, dust and the like. In many cases, the protective lid usually has a simple shape formed of a dielectric plate such as a synthetic resin.

In general, the directivity (that is, the collection characteristic of radio waves) of a feed horn having such a configuration is controlled by the aperture 10.
1, there is a diameter φ1 of the opening 101 (hereinafter referred to as an optimum opening diameter) that maximizes the antenna efficiency. Here, the antenna efficiency refers to the reception efficiency of the entire antenna, specifically, the ratio of the power that can be extracted to the total power of the radio waves arriving at the entire area of the reflector. The optimal opening diameter φ1 of the feed horn is
Regardless of the size of the reflector, it is uniquely determined according to the f / D value of the reflector (the ratio between the focal length f and the aperture diameter D of the reflector).

By the way, in consideration of the current housing situation in Japan, it is often difficult to secure an installation space for an antenna device using an excessively large reflector, so that further cost reduction and widespread use are required. Therefore, it is necessary to reduce the size of the antenna device. That is,
There is a market demand that the diameter D of the reflecting mirror should be as small as possible.

[0006] The feed horn shown in FIG. 20 is used for a single beam antenna having a single satellite to be received. Recently, however, a single radio wave from a plurality of satellites launched at different positions is used. A multi-beam antenna capable of receiving with the above antenna device has also been put to practical use. In this type of multi-beam antenna,
Feed horns are arranged corresponding to the respective collection positions of the reflectors of the radio waves from the respective satellites, and a receiving circuit unit is individually provided for each feed horn. Each feed horn and the corresponding receiving circuit are configured as an integrated receiving unit, and the number of such receiving units is equal to the number of receiving beams (the number of satellites to be received). One antenna device is constituted by a plurality of antenna devices.

FIG. 21 shows a simplified structure of a feed horn used in a dual beam antenna (antenna device for receiving two satellite radio waves) capable of receiving radio waves from two satellites. (A) of this figure shows a side cross section of the feed horn portion, and (b) shows a state viewed from the front (the side of the reflecting mirror not shown). This feed horn is shown in FIG.
The feed horn 103a has an opening 101a and a waveguide 102a having substantially the same structure as that shown in FIG. These two feed horns 103a, 10
3b is disposed such that the midpoint of each of the openings 101a and 101b substantially coincides with the focal point F of a not-shown reflecting mirror. Although not shown, the feed horn opening 101 is similar to the case of the single beam antenna described above.
Each of a and 101b is provided with a protective lid for preventing intrusion of rainwater, dust and the like.

The distance L between the two feed horns (the distance between the centers of the openings 101a and 101b) is mainly 2
It depends on the orbital distance between two satellites. Specifically, it is necessary to make the interval L smaller as the two satellites are closer, and to make the interval L larger as the two satellites are farther apart. However, if the orbital interval between the two satellites is too large, the offset amount (the amount of deviation between the focal point F of the reflector and the collection position of the radio wave from each satellite) increases, and the feed horn interval L shown in FIG. Since it becomes considerably large, the antenna efficiency is significantly deteriorated as compared with the single beam antenna. For this reason, such a dual beam antenna is used when receiving radio waves from two satellites relatively close to each other (with an orbit interval of about 8 to 30 °). Here, the orbit interval usually means a difference in longitude between satellites having a geosynchronous orbit above the equator.

[0009]

As described above, the conventional dual-beam antenna is configured by simply arranging two feed horns side by side, and is relatively close to two feed horns.
It has been used to receive radio waves from satellites (orbit intervals of about 8 to 30 degrees). However, when trying to receive radio waves from two satellites that are extremely close to each other (the orbital interval is about 4 °), the conventional dual beam antenna has the following problems. That is, in this case, since the offset amount becomes small, the feed horn interval L becomes too narrow, and L <φ
1, which makes it impossible to arrange two feed horns having the optimum opening diameter φ1 side by side. Hereinafter, this point will be specifically described.

FIG. 22 shows a case where radio waves from two satellites S1 and S2, which take a geosynchronous orbit on the equator while keeping a close distance from each other, are received by a dual beam antenna having a reflector 105 having an aperture diameter of D. In a simplified manner. As shown in this figure, the satellites S1, S
2 is located in geosynchronous orbits of 128 ° and 124 ° E east on the equator, respectively, the angle at which the two satellites are viewed from the earth, for example, Tokyo, ie, the straight line connecting the antenna installation point on the ground and the angular satellite, respectively. (Hereinafter, referred to as a sandwiching angle) θ is about 4.5 degrees.

As described above, the aperture diameter D of the reflecting mirror 105
Is required to be as small as possible,
At present, small reflectors having an opening diameter of about 45 cm are mainly used. Further, as described above, the optimum aperture diameter φ1 of the feed horn is f regardless of the size of the reflector.
/ D value, and the f / D value of this reflector is usually determined by the size of the antenna (reflector) for reasons such as commonization and simplification of products in design and manufacture. Regardless of the mirror aperture diameter, it is often set to a substantially constant value (for example, about 0.5).

Therefore, for example, the opening diameter of the reflecting mirror is set to 45c.
m, the f / D value of the reflecting mirror is 0.5, and the included angle θ is 4.
When a dual beam antenna for receiving radio waves in a frequency band of, for example, 12.5 GHz transmitted from the two satellites S1 and S2 of 5 degrees is designed, the optimal aperture diameter φ
1 is about 32 mm, and the optimal feed horn interval L1 is 25
mm. In this case, L1 <φ1, and as shown in FIG. 23, the openings of the feed horn partially overlap each other, so that two feed horns having the optimum opening diameter φ1 cannot be arranged side by side. In addition,
FIG. 21A shows a side cross section of the feed horn portion, and FIG. 21B shows a state viewed from the front (the side of the reflecting mirror 105).

In this case, the following two methods can be considered.
The first method is, as shown in FIG. 24, a method in which the feed horn interval is set to a value L2 larger than φ1, while maintaining the optimum opening diameter φ1 (32 mm in this case) of the feed horn. In the second method, as shown in FIG. 25, the feed horn opening diameter is set to a value φ2 smaller than L1 while keeping the feed horn interval at the optimum value L1 (here, 25 mm).
It is a method. FIG. 24A and FIG. 25A
24 shows a side cross section of the feed horn portion, and FIG.
(B) and FIG. 25 (b) both show a state viewed from the front (the side of the reflecting mirror 105).

However, in the first method, since the feed horn interval L2 is larger than the optimum interval L1,
It is out of the question because the radio waves cannot be guided sufficiently into the waveguides 102a and 102b. Further, in the second method, since the opening diameter φ2 of each feed horn is smaller than the optimum opening diameter φ1, the directivity of the feed horn is widened, and a state called spillover occurs. Note that this spillover means that when the antenna is regarded as a transmitting antenna, a decrease in the relative gain of the feed horn is, for example, 1 unit.
The maximum angular width of the radio wave emission direction that is within 0 dB is
It means that it becomes larger than the angle that allows the diameter of the reflector from the feed horn. Here, the antenna is regarded as a transmission antenna, but the spillover state is similarly defined when the antenna is a reception antenna by the reversible theorem.

As described above, the antenna efficiency is significantly reduced as compared with the single beam antenna. In addition, the antenna gain (the ability to capture radio waves as the whole antenna) also depends on the aperture diameter of the reflector itself. Specifically, as the aperture diameter of the reflecting mirror decreases, the gain also decreases. Therefore, a dual beam antenna for receiving radio waves from two satellites that are extremely close to each other is required.
In the case of using a reflector having a small diameter of cm, a sufficient antenna gain cannot be obtained, and the aperture diameter of the reflector has to be further increased.

As described above, conventionally, when it is attempted to receive radio waves from two satellites that are extremely close to each other with a dual beam antenna device having a small reflector, the optimum feed horn aperture diameter and the optimum feed horn Since the interval cannot be secured at the same time, there is a problem that the antenna gain is reduced due to the spillover described above, and a satellite radio wave reception C / N (carrier / noise) ratio is reduced due to an increase in reception noise. That is, it has been difficult to realize a compact dual-beam antenna capable of efficiently receiving radio waves from two adjacent satellites and obtaining a practical antenna gain and a satellite radio reception C / N. The above-mentioned problem is the same also in a multi-beam antenna for arranging three or more feed horns and receiving radio waves from three or more satellites.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has as its object to receive radio waves from a plurality of adjacent satellites with high sensitivity to obtain sufficient antenna gain and satellite radio reception C / N. An object of the present invention is to provide a small antenna device that can be used.

[0018]

SUMMARY OF THE INVENTION An antenna device according to the present invention is provided with a reflecting mirror for reflecting radio waves from a plurality of satellites and collecting them at different positions, and a radio mirror formed corresponding to each radio wave collecting position by the reflecting mirror. Waveguide, a dielectric member provided on each of the waveguides on the radio wave incident side, and radio wave electric conversion means for converting radio waves propagating through each waveguide through the dielectric member into electric signals. Have. Here, the dielectric member is formed of a rod-shaped body having a tapered shape such that the diameter decreases toward the radio wave incident side, and can be arranged so as to close each waveguide. It is. Radio waves from a plurality of satellites may be linearly polarized waves or circularly polarized waves.

In the antenna device according to the present invention, the dielectric member is provided on the radio wave incident side of each waveguide.
The effect improves the reception directivity in the waveguide,
The receiving efficiency as an antenna is improved.

[0020]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 shows a schematic configuration of an antenna device according to an embodiment of the present invention. As shown in FIG. 22, the antenna device 1 is configured as a dual beam antenna for receiving radio waves from two satellites S1 and S2 that draw a geosynchronous orbit on the equator while maintaining a close distance to each other. It is installed and used on the roof of a user's house, on a veranda, or the like. In the present embodiment, the satellites S1 and S2 will be described as communication satellites that transmit CS broadcast radio waves.
The present invention is not limited to this, and may be a broadcasting satellite that transmits BS broadcast radio waves. In CS broadcasting, linear polarization is used.
Circularly polarized waves are used in BS broadcasting.

As shown in FIG. 1, this antenna device 1
Is a reflecting mirror 11 that reflects radio waves transmitted from a plurality of satellites (not shown) and converges them at different positions, a clamp unit 13 fixed near the focal point of the reflecting mirror 11 by an arm 12, and a clamp unit 13. And a receiving unit 16 held rotatably. In the present embodiment, the description will be made assuming that the antenna device 1 is an offset-type antenna device in which the reception unit 16 does not hinder radio wave incidence. Reflector 11
For example, a parabolic reflector consisting of a part of a paraboloid of revolution is used. The receiving unit 16 includes a primary radiator 14 and a receiving circuit unit 15 called a converter that is formed integrally with the primary radiator 14. A connector (not shown) is provided below the receiving circuit unit 15, and one end of the coaxial cable 17 is connected to the connector. The other end of the coaxial cable 17 is connected to an indoor tuner (not shown). Here, the reflecting mirror 11 corresponds to a “reflecting mirror” in the present invention, and the receiving circuit unit 15 corresponds to “radio-electrical conversion means” in the present invention.

An elevation angle adjusting mechanism 21 for adjusting the elevation angle of the reflection mirror 11 is attached to the back side of the reflection mirror 11. The elevation angle adjustment mechanism 21 is attached to an azimuth angle adjustment mechanism 22 for adjusting the azimuth angle of the reflecting mirror 11, and the azimuth angle adjustment mechanism 22 is connected to a fixing portion 23 attached to a pillar of a veranda or the like. ing. And
The antenna device 1 including the reflecting mirror 11 and the receiving unit 16 is adjusted by adjusting the elevation angle and the directional angle of the reflecting mirror 11 by the elevation adjusting mechanism 21 and the azimuth adjusting mechanism 22.
The whole can be correctly oriented in the directions of the satellites S1 and S2.

Next, the configuration of the receiving unit 16 shown in FIG. 1 will be described in detail with reference to FIGS. here,
FIG. 2 shows a state in which the receiving unit 16 held by the clamp unit 13 is looked down from obliquely above, and FIG. 3 shows a state in which the receiving unit 16 is viewed from the front (the direction of arrow A in FIG. 2). 4 shows a state viewed from the side (the direction of arrow B in FIG. 2). FIG. 5 shows a state where the primary radiator 14 is viewed from the front with a cap 144 to be described later removed, and FIG. 6 shows a sectional view taken along the line YY 'in FIG. FIG. 7 is a sectional view taken along the line XX 'in FIG. 3, and FIG. 8 is a partially cutaway view of the receiving circuit unit 15 viewed from the direction of arrow C in FIG. . Here, FIG. 7 shows X in FIG.
It also corresponds to the -X 'section. FIG. 9 schematically shows a state in which the receiving unit 16 is separated into components. FIGS. 2, 5 and 6 show a state where the cap 144 is removed, and FIGS. 3 and 4 show a state where the cap 144 is attached. In FIG. 8,
A part of the cover plate 154 and the short-circuit waveguide 153 shown in FIG.
7 are omitted in FIGS. 7 and 8, and the coaxial cable 17 illustrated in FIG. 4 is omitted.

As shown in these figures, the primary radiator 14 constituting the receiving unit 16 includes a feed horn 141 in which two parallel waveguides 140a and 140b are formed, and each of the waveguides 140a and 140b. Dielectric rods 142a fitted on the entrance side (the side of the reflecting mirror 11),
142b and a cap 144 provided on the front surface of the feed horn 141. The dielectric rod 142a,
Each central axis of 142b and each central axis of the waveguides 140a and 140b coincide with each other. The cap 144
It is a protective cover for preventing intrusion of rainwater, dust, and the like. Here, the waveguides 140a and 140b correspond to “waveguides” in the present invention, and the dielectric bars 142a and 142b correspond to “dielectric members” in the present invention.

The feed horn 141 is shown in FIGS.
As shown in (1), it has waveguides 140a and 140b, and is formed as an integral conductor such as a metal die-cast. However, the portions including the respective waveguides may be formed separately, and these may be connected. Feed horn 141
For example, aluminum is used as the conductor constituting. The waveguides 140a and 140b are formed to have, for example, a circular cross section, but may have other cross sectional shapes. As shown in FIGS. 5 and 6, the waveguide 140a
An interval d for reducing mutual interference between radio waves focused toward each waveguide is ensured between the waveguide and the waveguide 140b. Accordingly, the diameter φ5 of the waveguides 140a and 140b is determined by the distance L between the centers of the waveguides 140a and 140b.
It is smaller than 3.

As shown in FIG. 2 and FIGS. 5 to 7, the radio wave incident side of the waveguides 140a and 140b (the reflecting mirror 11 side)
The dielectric rods 142a and 142b provided in
For example, it is formed of a dielectric such as polystyrene having a dielectric constant εr of about 2.45 to 2.65 or acrylic having a dielectric constant εr of about 2.2 to 3.2. These dielectric rods 142a and 142b operate as surface acoustic wave antennas. Here, the surface wave antenna is also called a traveling wave antenna, and has a function of increasing the intensity of the output electric field by aligning the phases of the output electric fields when the antenna device 1 is regarded as a transmission antenna. In other words, it functions as a lens. This effect is exhibited even when the antenna device 1 is used as a receiving antenna from the reversible theorem, and is effective to enhance the directivity of radio wave reception.
With the shape of 2b, the directivity of the antenna can be matched with the desired directivity.

The dielectric rod 142a in the present embodiment
Are respectively a conical portion 142a (1) having a tapered surface that becomes thinner toward the radio wave incident side, and a conical portion 142a
The waveguides 140a and 140 are integrally formed on the bottom side of (1).
0b, and a cylindrical projection 142a (3) integrally formed at the center of the rear side of the fitting 142a (2). . Cone 14
The tip of 2a (1) is slightly notched. Fitting part 1
42a (2) is fitted into the waveguide 140a. Here, as shown in FIG. 5, the diameter of the bottom surface of the cone 142a (1) is φ3, and the diameter of the tip surface of the cone 142a (1) is φ3.
4. The height of the cone 142a (1) is H, the fitting portion 142a
The diameter of (2) is the same as the diameter of the waveguides 140a and 140b.
It shall be described as 5. The dielectric rod 142b is also formed in the same shape as the dielectric rod 142a.

As shown in FIG. 2 to FIG. 4 and FIG. 7, the feed horn 141 is rotatably held by the clamp portion 13 and is fixed to the clamp portion 13 at an arbitrary rotational position by a fixing screw (not shown). It is fixed. As shown in FIGS. 3 and 4, the primary radiator 14 passes through the midpoint of the front end (radio wave incident side) of each of the waveguides 140 a and 140 b (that is, the focal point F of the reflecting mirror 11), and It is rotatable about an axis 148 parallel to the axes of the wave paths 140a and 140b.

As shown in FIG. 3 and FIG.
By adjusting the rotation angle of the primary radiator 14 around the center and adjusting the elevation angle and direction angle of the reflecting mirror 11 by the elevation angle adjustment mechanism 21 and the azimuth angle adjustment mechanism 22 shown in FIG. Each radio wave transmitted from the satellites S1 and S2 and reflected by the reflector 11 is transmitted to the primary radiator 1
4 and the dielectric rods 142a, 1 of the waveguides 140a, 140b.
Waves are respectively collected toward 42b.

Although not shown in the present embodiment, waveguides 140a and 140b in feed horn 141 are not shown.
Around the front opening of the waveguide 140, a noise component jumping from a direction other than the incident direction of the radio wave from the satellite is
a, 140b, a groove called a corrugated ring for preventing the intrusion into the inside may be formed. If the groove depth of this corrugated ring is set to be a quarter of the wavelength of the radio wave, the characteristic impedance of the groove portion becomes
Theoretically, the surface current becomes infinite, and the surface current generated by the radio wave incident from the outside does not flow to the feed horn 114 side, and the current generated by the radio wave of the incident wave does not flow to the outside. Thereby, the noise component is reduced, and the receiving sensitivity is further improved.

As shown in FIGS. 7 and 8, the receiving circuit unit 15 includes a housing 151 made of a conductor,
1, a short-circuit waveguide 153 made of a conductor disposed so as to cover a main part of the substrate module 152, and a conductor for sealing the inside of the housing 151. And a cover plate 154 made of Here, the housing 151 is formed integrally with the primary radiator 14 as a metal die-cast made of, for example, aluminum or the like. However, the present invention is not limited thereto, and the two may be formed separately and connected.

A grounding pattern 152a (not shown in FIG. 8) is formed on the back side (the side from which radio waves arrive) of the substrate module 152, and this is in contact with the rear end faces of the waveguides 140a and 140b of the feed horn 141. are doing. A grounding pattern 152b patterned corresponding to the cross-sectional shape of the waveguides 140a and 140b and a horizontal linear polarization (hereinafter, referred to as horizontal Horizontal probes 1521a and 1521b as receiving electrodes for
Vertical probes 1522a and 1522b as receiving electrodes for vertical linear polarization (hereinafter referred to as vertical polarization).
And other circuit patterns. Further, on the front side of the board module 152, various circuit components, elements, and the like (not shown) constituting the receiving circuit are mounted. Each of the above electrode patterns and circuit patterns is formed of a thin film conductor such as a copper foil. In FIG. 7, the thickness of each pattern is drawn thicker than the actual one.

In FIG. 8, a horizontal probe 1521a and a vertical probe 1522a are receiving electrodes provided corresponding to the waveguide 140a. Among these, the horizontal probe 1521a converts the horizontal polarization propagated through the waveguide 140a into an electric signal, and the vertical probe 1522a converts the vertical polarization propagated through the waveguide 140a into an electric signal. . On the other hand, the horizontal probe 1521b
The vertical probe 1522b is a receiving electrode provided corresponding to the waveguide 140b. Of these, the horizontal probe 1521b converts the horizontal polarization transmitted through the waveguide 140b into an electric signal, and the vertical probe 1522b converts the vertical polarization transmitted through the waveguide 140b into an electric signal. .

The short-circuit waveguide 153 is connected to the substrate module 15.
2 from the front side of the housing 151.
And is fixed to the housing 151 by screws (not shown) or the like. In this state, the short-circuited waveguide 153 is in surface contact with only the ground pattern 152b, and thus the horizontal probes 1521a and 1521b
And the vertical probes 1522a and 1522b are shielded from the surroundings. The short-circuit waveguide 153 (FIG. 1) propagates through the waveguides 140a and 140b and
52 are reflected by the short-circuit portions 153a and 153b, and are reflected again by the horizontal probes 1521a and 1522a or the vertical probes 1521 of the board module.
b, 1522b, for example, by die-casting a metal such as aluminum. The short-circuit waveguide 153 allows the horizontal probes 1521a, 1522
a, or the reception electric field strength at the vertical probes 1521b and 1522b can be increased. The cover plate 154 is
It is for sealing the inside of the housing 151 to prevent rainwater from entering and for electromagnetically shielding the inside of the housing 151 from the outside, and is formed of a conductor.

FIG. 9 shows a simplified state in which the receiving unit 16 is separated into its components. As shown in this figure, the board module 152 is mainly configured to include a circuit called a converter that performs frequency conversion and amplification of a received signal.

Specifically, the board module 152 includes the four probes (horizontal probes 1521a and 1521b and vertical probes 1522a and 1522b) for converting a linearly polarized radio wave into an electric signal, and a horizontal probe 1521a. Alternatively, the polarization changeover switch unit 15 that performs switching so as to select one of the vertical probes 1522a
24a and a polarization changeover switch unit 1524b that switches so as to select one of the horizontal probe 1521b and the vertical probe 1522b.

The board module 152 also includes high-frequency amplifiers 1523a and 1523b provided between the horizontal probe 1521a and the vertical probe 1522a and the polarization switch unit 1524a, respectively, and a polarization switch between the horizontal probe 1521b and the vertical probe 1522b. High-frequency amplifiers 1523c and 1523d are provided between the switch unit 1524b and the switch unit 1524b.

Further, the board module 152 is connected to a satellite switch 1525 for switching so as to select one of the outputs of the polarization switch 1524a and 1524b, and an output terminal of the satellite switch 1525. High-frequency amplifier circuit 1523e and a mixing circuit (mixer) connected to the output terminal of high-frequency amplifier circuit 1523e
A local oscillation circuit 1527 for supplying a local oscillation signal having a predetermined frequency to the mixing circuit 1526;
Intermediate frequency amplifier 1523 connected to the output terminal of 526
f.

The output terminal of the intermediate frequency amplification circuit 1523f
It is connected to a connector 155 to which the coaxial cable 17 (FIGS. 3 and 5) is connected via a DC cut circuit 1528 for removing a DC component. This board module 1
52 also includes a power supply 1530 for supplying stable power to each of the above circuits, and an RF cut circuit 1531 for removing high-frequency components and received signal components from the output of the power supply 1530.

Polarization changeover switches 1524a and 1524
b and the satellite switch unit 1525 perform a switching operation in response to a switching signal from a control unit (not shown), thereby selecting one of the four probes and connecting to the high-frequency amplifier circuit 1523e. It has become. The control unit outputs the switching signal in response to a received polarization selection command transmitted via a coaxial cable 17 from a receiver (tuner) (not shown) installed indoors, for example. It has become.

The high frequency amplifier circuits 1523a to 1523e are, for example, 12 GHz received by the horizontal probe 1521a or the like.
This is a circuit for amplifying a high-frequency signal in a band as it is, and is configured using an extremely low-noise amplifying element such as a GaAs-FET (gallium arsenide field effect transistor).

The mixing circuit 1526 includes the high-frequency amplification circuit 15
For example, a high frequency signal of, for example, 12 GHz band amplified at 23 e and, for example, 11 GHz supplied from a local oscillation circuit 1527.
Band, which is a frequency band that can be transmitted by the coaxial cable 17, for example, 1G.
It outputs an intermediate frequency signal (IF signal) in the Hz band. For example, if the frequency of the received high-frequency signal is 1
Assuming that the frequency is 2.25 GHz to 12.75 GHz and the frequency of the local oscillation signal is, for example, 11.2 GHz, the frequency of the IF signal is 1.05 GHz to 1.55 GHz. The intermediate frequency amplifying circuit 1523f is necessary for compensating signal attenuation when transmitting the coaxial cable 17 to the IF signal output from the mixing circuit 1526 and reducing image quality deterioration caused by a noise factor of a tuner (not shown). Up to the level,
Perform amplification.

Next, a description will be given of an adjustment method, operation and operation of the antenna device having the above-described configuration.

First, a method of adjusting the antenna device will be described. For this adjustment, the primary radiator 14 and the receiving circuit unit 15
There is adjustment of the rotation angle of the receiving unit 16 configured integrally with the above, adjustment of the elevation angle of the entire antenna device including the reflecting mirror 11 and the receiving unit 16, and adjustment of the azimuth angle of the entire antenna device.

In the antenna apparatus according to the present embodiment, first, the entire receiving unit 16 including the primary radiator 14 is rotated about a midpoint axis 148 (FIG. 4) passing through the focal point F, so that the satellites S1, Adjustment is performed so that the central portions of the openings 141a and 141b are respectively adjusted to the positions where the respective radio waves from S2 are to be collected, and after the adjustment, the primary radiator 14 is attached to the clamp portion 13 by a fixing screw or the like (not shown). Fix it. In this case, since the rotation angle of the primary radiator 14 is determined mainly by the longitude of the antenna installation point, the rotation angle of each installation point is graduated around the primary radiator 14 in advance, and the user sets the receiving unit according to this scale. The rotation adjustment of 16 may be performed.

The reason why the rotation adjustment of the feed horn 141 is necessary is as follows. That is,
The satellites to be received are the two satellites S1 and S2 that have a geosynchronous orbit above the equator, but when these satellites are viewed from the antenna installation point on the ground, the elevation angles of both satellites differ depending on the longitude and latitude of that point. The position of collection of radio waves from each satellite by the reflecting mirror 11 changes according to the difference between the elevation angles. Therefore, in order to obtain the best receiving sensitivity, it is necessary to adjust the two waveguides 140a and 140b of the receiving unit 16 to each actual collecting position.

After the rotation angle of the receiving unit 16 has been adjusted in this way, the elevation angle and the azimuth angle of the antenna device are adjusted. First, the elevation angle adjustment mechanism 21 shown in FIG. 1 roughly adjusts the elevation angle of the entire antenna, and then the azimuth angle adjustment mechanism 22 coarsely adjusts the azimuth angle of the entire antenna. Further, the radio wave is actually received in this state, and the elevation angle and the azimuth angle are finely adjusted so that the reception state becomes the best.

Next, the operation of the antenna device will be briefly described.

High-frequency CS broadcast waves transmitted from the satellites S1 and S2 (FIG. 22) are reflected by the reflector 11 (FIG. 1), and are guided by the waveguides 140a and 140 of the primary radiator 14.
b are collected toward the dielectric rods 142a and 142b provided in the waveguides 140a and 140b, respectively.
Is led to the substrate module 152 of FIG. At this time, since the dielectric rods 142a and 142b function as surface acoustic wave antennas as described above, the directivity as a receiving antenna increases.

In this case, the CS broadcast waves transmitted from the satellites S1 and S2 are two kinds of polarized waves, that is, a horizontal direction and a vertical direction. Varies slightly depending on the longitude of the point. However, in the present embodiment, as described above, the feed horn 1 corresponding to the elevation angle difference between the two satellites S1 and S2.
41, the four receiving electrodes (horizontal probe 1521a,
1521b and vertical probes 1522a, 1522
The arrangement direction of b) substantially coincides with each polarization direction of the received radio wave. Therefore, conversion efficiency is improved, which is advantageous.

Now, referring to FIG.
2 reach the substrate module 15
Each probe (horizontal probe 15) provided on the front side of
21a, 1521b and vertical probe 1522a,
1522b), the signals are converted into high-frequency electric signals, and are selectively input to the high-frequency amplifier circuit 1523e. At this time, selection of which of the received signals obtained from the four probes is to be input to the high-frequency amplifier circuit 1523e is performed by a controller (not shown) by setting the polarization switching switches 1524a and 1524b and the satellite switching switch 1525. It is done by switching.

Now, the high-frequency amplification circuit 15
The high-frequency reception signal input to 23e is amplified at the same frequency and input to the mixing circuit 1526. The mixing circuit 1526 heterodyne-detects the high-frequency signal amplified by the high-frequency amplification circuit 1523e and the local oscillation signal supplied from the local oscillation circuit 1527, outputs an IF signal having the difference frequency, and outputs the IF signal having the difference frequency. To enter. The intermediate frequency amplification circuit 1523f includes the mixing circuit 15
The IF signal output from 26 is amplified to a required level. The IF signal thus amplified is supplied to the DC cut circuit 1
528 through the connector 155 to the coaxial cable 17
It is sent to a receiver (tuner) (not shown) indoors via a (not shown), and is used for screen display on a television receiver (not shown).

Next, the operation of the antenna device according to this embodiment will be described with reference to specific numerical examples.

In FIGS. 5 and 6, the waveguide 140
a and 140b are spaced from each other by satellites S1 and S2 (FIG. 2).
L3 depends on the relative distance (accurately, the longitude difference between the geosynchronous orbit positions of the respective satellites), and the smaller the longitude difference between the satellites S1 and S2, the smaller the L3. For example, if the satellite S1 is 128
Assuming that the satellite S2 is located at 124 degrees east longitude, the longitude difference between the two is only 4 degrees. For example, the angle θ at which both satellites are seen from Tokyo (the pinch angle θ) is about 4.5 degrees. Becomes

Here, the opening diameter D of the reflecting mirror 11 is set to, for example, 4
5cm and the focal length f is 22.5c, for example.
Assuming that the distance is about m, the f / D value, which is the ratio between the focal length and the antenna aperture, is about 0.5. Assuming that the radio wave received from each satellite is linearly polarized in the frequency band of 12.5 GHz, the dimensions of each part of the primary radiator 14 shown in FIGS. 5 and 6 are preferably as follows, for example. is there.

The diameter φ5 of the waveguides 140a and 140b = 1
7.5 mm Center-to-center distance L3 between waveguides 140a and 140b = 25 mm Distance d between waveguides 140a and 140b = 7.5 mm Diameter φ3 at bottom of conical portion of dielectric rods 142a and 142b
18.0 mm Diameter φ4 of tip surface of conical part of dielectric rods 142a and 142b
= 5.0 mm Height H of the conical part of the dielectric rods 142a and 142b = 30m
m Dielectric constant ε of the material constituting the dielectric rods 142a and 142b
r = 3.0 The protrusions 142a of the dielectric rods 142a and 142b
(3) is for reducing the reflection loss of the radio wave, and it is preferable that the diameter is, for example, about 6.0 mm and the height is about 5.0 mm.

FIG. 10 shows an example of the measurement result of the directivity of the primary radiator 14 for which the numerical values are set as described above. FIG. 11 shows an example of a measurement result of directivity of a primary radiator 14 ′ having no dielectric rods 142 a and 142 b as a comparative example with respect to the present embodiment. The primary radiator 14 'used to obtain the measurement results in FIG. 11 has the same shape, dimensions, and the like as the primary radiator 14, except that the primary radiator 14' does not have the dielectric rods 142a and 142b. These results are obtained when the satellite S1 at 128 degrees east longitude is measured as a reception target. The horizontal axis indicates the offset angle (unit is 'degree'), and the vertical axis indicates the relative gain (unit is 'dB'). The offset angles in FIGS. 10 and 11 are, as shown in FIGS. 12 and 13,
This is the swing angle when the radio wave incident direction to the primary radiator 14 (or the radio wave emission direction from the primary radiator 14) is shifted from the maximum gain direction and is swung vertically or horizontally. FIGS. 12 and 13 show a simplified view of the antenna device 1 as viewed from the lateral direction.

As can be seen from FIGS. 10 and 11, the relative gain of the primary radiator 14 decreases as the direction of the radio wave incidence (or emission) becomes farther from the direction of the radio wave incidence (or emission) where the relative gain becomes maximum. Somewhere, -10
The value of dB is interrupted. The decrease in the relative gain is 10
Assuming that the range of the azimuth angle within the range of dB is referred to as a 10 dB bandwidth, the 10 dB bandwidth of the primary radiator 14 in the present embodiment is approximately 87.degree., as shown in FIGS. 6 degrees. This value is
The angle of 85 to which the primary mirror 14 looks into the reflecting mirror 11
This is an optimum value substantially equal to 90 degrees, and there is little reduction in antenna gain and reception noise.

On the other hand, a dielectric rod 142 as a comparative example
a, the primary radiator 14 'without 142b has 10d
The B band width is about 1 as shown in FIGS.
It will be 12 degrees. That is, primary radiator 1 of the present embodiment
At 4, the 10 dB bandwidth is substantially equal to the angle at which the reflector 11 is viewed from the primary radiator 14,
In the primary radiator 14 'of the comparative example, the 10 dB bandwidth is
The angle greatly exceeds the viewing angle of the reflecting mirror 11 from the primary radiator 14 '. This excess is called spillover,
This causes a reduction in antenna gain and an increase in reception noise.

FIGS. 14 and 15 each show an example of the measurement results of the reception directivity when radio waves from two satellites S2 and S1 are received by the antenna device 1 having the primary radiator 14 according to the present embodiment. Is represented. Here, FIG. 14 shows the measurement result of the directivity for the radio wave received from the satellite S2, and FIG. 15 shows the measurement result of the directivity for the radio wave received from the satellite S1. In these figures, the horizontal axis indicates the offset angle (unit is 'degree'), and the vertical axis indicates the relative gain (unit is 'dB') of the antenna. The offset angle in FIGS. 14 and 15 is a swing angle when the direction of the antenna device is swung up and down or left and right from the direction in which the maximum gain is obtained for each satellite.

FIGS. 16 and 17 show, respectively,
FIG. 14 shows an example of a measurement result of reception directivity when radio waves from two satellites S2 and S1 are received by an antenna device including the primary radiator 14 'of the comparative example. Here, FIG. 16 shows the measurement result of the directivity for the radio wave received from the satellite S2, and FIG. 17 shows the measurement result of the directivity for the radio wave received from the satellite S1. In these figures,
The horizontal axis and the vertical axis are the same as those in FIGS.

In the antenna device 1 of this embodiment having directivity as shown in FIGS. 14 and 15, the satellite S
The antenna gains for 1 and S2 were both 34 dBi. On the other hand, in the antenna device as a comparative example having directivity as shown in FIG. 16 and FIG.
The antenna gain for S2 is 33.6 dB each.
i, 33.7 dBi. That is, in the present embodiment, the antenna gain is 0.3 to 0.4 with respect to the comparative example.
It is improved by about dB. Note that the unit 'dBi' is a unit indicating how much gain is given to an isotropic wave source.

When the reception noise of the antenna device 1 of the present embodiment and the antenna device of the comparative example were measured, the antenna devices 1 of the present embodiment showed that the satellites S1, S
2 are -44.5 dBm /
In contrast to 39 MHz and -44.4 dBm / 39 MHz, in the antenna device 1 of the present embodiment, the satellite S
1 and S2 are -44.3d, respectively.
Bm / 39 MHz and -44.1 dBm / 39 MHz. That is, in the present embodiment, for the comparative example,
The reception noise is reduced by about 0.2 to 0.3 dB. These values indicate the noise level per 39 MHz frequency bandwidth when 0 dB is 1 mW.

When the reception C / N (carrier / noise) ratio of the antenna device 1 of the present embodiment and the antenna device of the comparative example was measured, the satellites S1 and S2 of the antenna device 1 of the present embodiment were measured. Has been obtained that the reception C / N ratio of the antenna device of the comparative example is improved by about 0.6 dB with respect to the reception C / N ratio of the satellites S1 and S2 in the antenna device of the comparative example.

As described above, according to the antenna device of the present embodiment, the waveguides 140a, 140a of the primary radiator 14
Since the dielectric rods 142a and 142b are provided on the respective 40b, the two very close satellites S1 and S2 are provided.
When trying to receive a radio wave from a single dual beam antenna device, the waveguides 140a and 140b
Is set to the optimum value, and the waveguide 140
The 10 dB bandwidth can be set to an optimum value while the diameters of a and 140b are small enough not to overlap each other, and the directivity of the primary radiator 14 can be optimized. Therefore, in the present embodiment, the dielectric rod 142
There is no spillover that occurs when the a and 142b are not provided, and there is no problem such as a decrease in antenna gain or a decrease in the C / N ratio of satellite radio wave reception due to an increase in reception noise. Therefore, even in a dual beam antenna device using a small parabolic reflector, it is possible to efficiently separate linearly polarized radio waves from two approaching satellites and receive each with a sufficient antenna gain. .

[Second Embodiment] Next, a second embodiment of the present invention will be described.
An embodiment will be described.

FIG. 18 shows a circuit configuration of a board module 152 'in an antenna device according to a second embodiment of the present invention. The antenna device according to the present embodiment
This is for receiving circularly polarized waves from satellites for BS broadcasting. Note that, in this figure, the same elements as those of the primary radiator 14 (FIG. 9) of the first embodiment are denoted by the same reference numerals, and description thereof will be omitted as appropriate.

As shown in FIG. 18, the board module 152 'includes horizontal probes 1521a and 1521b and vertical probes 1522a and 1522b for converting a linearly polarized radio wave into an electric signal.
21a and a power distributor 15 connected to a vertical probe 1522a via a phase adjuster 1536a.
35a and a horizontal probe 1521b connected to a vertical probe 1522b and via a phase adjuster 1536b.
A power distributor 1535b connected to the
It includes high-frequency amplifiers 1537a and 1537b connected to 35a and 1535b, respectively, and a satellite switch unit 1525 for switching to select one of the high-frequency amplifier 1537a and the high-frequency amplifier 1537b. Note that the configuration after the output terminal of the satellite changeover switch unit 1525 is the same as in the case of FIG. 9 described above, and a description thereof will be omitted. The configuration other than the board module 152 'is the same as that of the first embodiment.

The board module 152 'having such a structure is provided.
Then, the horizontal probes 1521a and 1521b output a reception signal corresponding to the horizontal polarization component of the incident circularly polarized radio wave, and the vertical probes 1522a and 1522b.
Outputs a received signal corresponding to the vertical polarization component of the incident circularly polarized radio wave.

The phase adjuster 1536a is connected to the vertical probe 1
The phase of the received signal obtained at 522a is adjusted and input to power divider 1535a. The power divider 1535a distributes power with the same phase and the same amplitude to the received signal obtained by the horizontal probe 1521a and the received signal output from the phase adjuster 1536a, combines the received signals, and outputs the resultant. The output signal from the power divider 1535a is
The satellite S that has passed through 42a and entered the waveguide 140a
1 is a reception signal having a phase and an amplitude corresponding to the circularly-polarized radio wave from No. 1;
The signal is input to one terminal of the satellite changeover switch unit 1525 via the terminal 37a.

On the other hand, the phase adjuster 1536b adjusts the phase of the received signal obtained by the horizontal probe 1521b and inputs the adjusted signal to the power divider 1535b. Power distributor 1535b
Distributes power with the same phase and the same amplitude to the reception signal output from the phase adjuster 1536b and the reception signal obtained by the vertical probe 1522b, combines the power, and outputs the resultant signal. The output signal from power divider 1535b is a reception signal having a phase and an amplitude corresponding to the circularly polarized radio wave from satellite S2 that has passed through dielectric rod 142b and entered waveguide 140b. The signal is input to the other terminal of the satellite switch unit 1525 via the high-frequency amplifier circuit 1537b.

Waveguide 14 for receiving radio waves from satellite S1
0a, for example, the vertical probe 152
If the phase of the output signal from the phase adjuster 1536a connected to 2a is delayed by π / 2 (90 degrees) from the phase of the output signal from the horizontal probe 1521a,
This antenna device operates as a right-handed circularly polarized antenna. Further, a waveguide 140 for receiving a radio wave from the satellite S2
Looking at the side b, for example, the horizontal probe 1521
If the phase of the output signal from phase adjuster 1536b connected to b is delayed by π / 2 from the phase of the output signal from vertical probe 1522b, this antenna apparatus operates as a right-handed circularly polarized antenna. .

The satellite switch unit 1525 performs a switching operation in response to a switching signal from a control unit (not shown) to select one of the high-frequency amplifier circuit 1537a and the high-frequency amplifier circuit 1537b, and to select the high-frequency amplifier circuit 1523e. Output to Subsequent operations are the same as in the case of FIG. 9 in the first embodiment, and a description thereof will be omitted.

As described above, the antenna apparatus of the present embodiment can receive circularly polarized radio waves used in BS broadcasting and the like. Also, in the present embodiment, the waveguides 140a and 140
Dielectric rods 142 provided on the entrance side of Ob, respectively.
Due to the effects of a and 142b, problems such as a decrease in antenna gain due to spillover and a decrease in the C / N ratio of satellite radio wave reception due to an increase in reception noise do not occur. Therefore, even with a dual beam antenna device using a small parabolic reflector, it is possible to efficiently separate circularly polarized radio waves from two adjacent satellites and receive them with sufficient antenna gain. is there.

[Third Embodiment] Next, a third embodiment of the present invention will be described.
An embodiment will be described.

FIG. 19 schematically shows a state in which the receiving unit in the antenna device according to the third embodiment of the present invention is separated into components. In this figure, the same components as those shown in FIG. 9 are denoted by the same reference numerals, and description thereof will be omitted as appropriate.

The antenna device according to the present embodiment is for receiving radio waves from three satellites that are close to each other. As shown in FIG. 19, the receiving unit 26 of this antenna device includes a primary radiator 24, a substrate module 252, and a short-circuit, instead of the primary radiator 14, the substrate module 152, and the short-circuit waveguide 153 in FIG. A waveguide 253 is provided. The primary radiator 24
A feed horn 241 having three waveguides 240a, 240b, 240c is provided in place of the feed horn 141 in FIG. 9, and the dielectric rods 142a, 142 in FIG.
In this embodiment, dielectric bars 242a, 242b, 242c are provided in place of 2b.

The board module 252 is provided with a horizontal probe 252 for converting a linearly polarized radio wave into an electric signal.
1a-2521c, and vertical probe 2522a-2
522c, a polarization changeover switch unit 2524a that switches so as to select one of the horizontal probe 2521a and the vertical probe 2522a, and a horizontal probe 2521
and a polarization switch unit 2524c for switching to select one of the horizontal probe 2522b and the vertical probe 2522c, and a polarization switch unit 2524c for switching to select one of the horizontal probe 2521c and the vertical probe 2522c. I have. The substrate module 252 also includes a horizontal probe 2521a and a vertical probe 2521a.
High-frequency amplifiers 2523a and 2523b provided between the polarization switching unit 22a and the polarization switching unit 2524a, respectively;
Horizontal probe 2521b and vertical probe 2522b
High-frequency amplifiers 2523c and 2523d provided between the polarization switch unit 2524b and the high-frequency amplifiers 2523e and 2523f provided between the horizontal and vertical probes 2521c and 2522c and the polarization switch unit 2524c, respectively. It has.
Further, the board module 252 includes a satellite changeover switch unit 2525 that performs switching so as to select any one of the outputs of the polarization changeover switch units 2524a to 2524c.
A high-frequency amplifier circuit 1523e connected to the output terminal of the satellite changeover switch unit 2525. The subsequent circuit configuration is the same as that of FIG. 9, and the description thereof will be omitted.
The configuration other than the board module 252 is the same as that of the first embodiment.
This is the same as the embodiment.

According to the antenna apparatus of this embodiment including the receiving unit 26 having such a configuration, it is possible to receive linearly polarized radio waves from three satellites close to each other. Also, in the present embodiment, similarly to the case of the above-described first and second embodiments, the waveguides 240a to 240a
Dielectric rods 2 provided at each entrance side of 240c
By the operations of 42a to 242c, problems such as a decrease in antenna gain due to spillover and a decrease in satellite radio reception C / N ratio due to an increase in reception noise do not occur. Therefore, even with a dual-beam antenna device using a small parabolic reflector, it is possible to efficiently separate linearly polarized radio waves from three approaching satellites and receive each with a sufficient antenna gain. is there.

Although the antenna device according to the present embodiment has been described as a linearly polarized receiving antenna, similar to the second embodiment, the horizontal or vertical polarized wave reception is performed by the phase adjuster. By adjusting any phase of the signal and performing power distribution by the power distributor,
It is also possible to receive circularly polarized waves from three satellites.

As described above, the present invention has been described with reference to some embodiments. However, the present invention is not limited to these embodiments, and can be variously modified. For example, in each of the above embodiments, the dielectric rods 142a, 142b, 242a, 242
The main part of b, 242c is made conical,
Other shapes are also possible.

Further, in the above embodiment, a dual beam antenna device capable of receiving radio waves from two satellites,
And a triple beam antenna device capable of receiving radio waves from three satellites has been described. However, the present invention is not limited to these, and a multi-beam antenna device capable of receiving radio waves from four or more satellites is described. It is also possible to apply.

In each of the above embodiments, an offset type parabolic antenna has been described as an example. However, the present invention is not limited to this, and can be applied to other types of parabolic antennas, Cassegrain antennas, Gregory antennas, and the like. is there.

[0084]

As described above, according to the antenna device according to any one of the first to fourth aspects, the antenna device is formed corresponding to each of the positions at which the reflectors collect the radio waves from a plurality of satellites. A dielectric member is provided on each radio wave incident side of the waveguide, and the radio waves propagating through each waveguide through these dielectric members are converted into electric signals.
The reception directivity in the waveguide is improved, and the reception efficiency as an antenna is improved. Therefore, for example, when radio waves from satellites that are close to each other are received using a small reflector, the two waveguides overlap each other while securing the optimal waveguide spacing corresponding to each satellite position spacing. Even if it is reduced to such an extent that the dielectric member does not exist, problems such as a decrease in antenna gain due to spillover and a decrease in satellite radio reception C / N ratio due to an increase in reception noise do not occur. That is, even when a small reflecting mirror is used, there is an effect that radio waves from two approaching satellites can be efficiently separated and received at a practical level of sensitivity.

[Brief description of the drawings]

FIG. 1 is an external perspective view illustrating an overall configuration of an antenna device according to an embodiment of the present invention.

FIG. 2 is an external perspective view illustrating a configuration of a receiving unit in FIG.

FIG. 3 is a front view illustrating a configuration of a receiving unit in FIG.

FIG. 4 is a side view illustrating a configuration of a receiving unit in FIG.

FIG. 5 is a front view of a primary radiator of the receiving unit in FIG. 1;

FIG. 6 is a partial sectional view of a primary radiator of the receiving unit in FIG. 1;

FIG. 7 is a cross-sectional view illustrating a structure of a receiving unit in FIG.

FIG. 8 is a partially cutaway rear view showing the structure of the receiving unit in FIG. 1;

FIG. 9 is a simplified perspective view showing the structure of a receiving unit in FIG. 1;

FIG. 10 is a diagram illustrating an example of a measurement result obtained for the directivity of the receiving unit in FIG. 1;

FIG. 11 is a diagram illustrating an example of a measurement result obtained for the directivity of a receiving unit as a comparative example with respect to the present embodiment.

FIG. 12 is a diagram simply illustrating a state in which the antenna device is viewed from the lateral direction, and is a diagram for describing a state in which the directivity of the primary radiator is good.

FIG. 13 is a diagram simply illustrating a state in which the antenna device is viewed from the lateral direction, and is a diagram for explaining a state in which the directivity of the primary radiator is not good.

FIG. 14 is a diagram illustrating an example of a measurement result obtained for the directivity of the antenna device according to the present embodiment.

FIG. 15 is a diagram illustrating another example of the measurement results obtained for the directivity of the antenna device according to the present embodiment.

FIG. 16 is a diagram illustrating an example of a measurement result obtained for the directivity of an antenna device as a comparative example with respect to the present embodiment.

FIG. 17 is a diagram illustrating another example of the measurement results obtained for the directivity of the antenna device as a comparative example with respect to the present embodiment.

FIG. 18 is a circuit diagram illustrating a simplified circuit configuration of a board module of an antenna device according to a second embodiment of the present invention.

FIG. 19 is a perspective view showing a simplified structure of a receiving unit in the antenna device according to the third embodiment of the present invention.

FIG. 20 is a structural diagram showing a simplified structure of a feed horn used for a single beam antenna.

FIG. 21 is a structural diagram showing a simplified structure of a feed horn used for a dual beam antenna.

FIG. 22 is an explanatory diagram for explaining how radio waves from two satellites are collected by a parabolic reflector to a primary radiator.

FIG. 23 is an explanatory diagram for describing a problem when a small dual beam antenna is configured to receive radio waves from two adjacent satellites.

FIG. 24 is another explanatory diagram for describing a problem when a small dual beam antenna is configured to receive radio waves from two adjacent satellites.

FIG. 25 is still another explanatory diagram for describing a problem when a small dual beam antenna is configured to receive radio waves from two adjacent satellites.

[Explanation of symbols]

11 reflector, 14 primary radiator, 15 receiving circuit
16 receiving units, 140a, 140b, 240a to
240c: waveguide, 141, 241: feed horn,
142a, 142b, 242a to 242c: dielectric rod,
S1, S2 ... satellite

 ────────────────────────────────────────────────── ─── Continued on the front page F term (reference) 5J020 AA03 BA10 BA19 BB01 BC06 CA04 DA02 DA06 DA07 DA09 5J021 AA01 AB07 BA01 CA03 CA06 DA03 FA23 FA26 FA31 FA32 GA02 HA02 HA05 HA07 JA05 JA06 JA07 5K062 AA09 AB01 AC01

Claims (4)

[Claims] 1. A reflector which reflects radio waves from a plurality of satellites and collects them at different positions, a waveguide formed corresponding to each radio wave collection position by the reflector, and each of the waveguides A dielectric member provided on each of the radio wave incident sides, and radio wave electric conversion means for converting radio waves propagating through each of the waveguides through the dielectric member into electric signals. Antenna device. 2. The dielectric member is formed of a rod-shaped body having a tapered shape such that a diameter decreases toward a radio wave incident side, and is arranged so as to close each of the waveguides. The antenna device according to claim 1, wherein: 3. The antenna device according to claim 1, wherein the radio waves from the plurality of satellites are linearly polarized waves. 4. The antenna device according to claim 1, wherein the radio waves from the plurality of satellites are circularly polarized waves.