CN1172555A - Antenna - Google Patents

Abstract

When the antenna element is expanded, a helical element(4)acts as a parasitic element, and a high-frequency current flows through an element conductor(3), causing the helical element(4)to act as a parasitic element which is excited by a high frequency wave way. When the antenna element is housed, electrical energy is fed to the upper end of the helical element(4)from the upper end of an upper conductor section(6), and the overlapping parts of the helical element(4)and conductor section(6)form an L-C parallel resonance circuit. Therefore, the antenna performs a two-resonance operation.

Description

antenna

The invention relates to a free-sliding antenna arranged on a shell, especially suitable for a portable radiotelephone.

An outline of such a conventional antenna is shown in FIGS. 5(A) and (B). The A-type antenna shown in FIG. 5(A) is composed of an antenna element and a helical element 104 provided on an insulating portion 106 at the upper end of a conductor element 103 as proposed in JP-A-6-216630. The antenna element can slide in the helical element 104 and be retracted into the housing 100 , and the retracted antenna element can be extended from the housing 100 . The spiral element 104 is fixedly disposed in the upper protruding portion of the casing 100 .

The state of the antenna element of this antenna after being slid and extended is shown in (a) of FIG. 5(A). In this case, the signal generated from the signal source 102 inside the casing 100 is supplied to the power supply unit 105 through the matching circuit (MC) 101 . The power supply part 105 is electrically connected to the lower end of the conductor element 103 and the lower end of the helical element 104, so the conductor element 103 and the helical element 104 are in working state.

On the other hand, the state where the antenna element is slid into the housing 100 is shown in (b) of FIG. 5(A). In this case, the signal generated from the signal source 102 in the housing 100 passes through the matching circuit (MC) 101, and is supplied to the power supply part 105. At this time, the power supply part 105 is only electrically connected to the lower end of the spiral element 104. Therefore, only The helical element 104 is in working condition.

In this case, the insulating portion 106 formed at the upper end of the antenna element is located in the helical element 104 so that the helical element 104 is not affected by the antenna element.

In addition, an outline of a conventional B-type antenna having a configuration different from the antenna described above is shown in FIG. 5(B). Such an antenna, as proposed in JP-A-2-271701, consists of an antenna element and a helical element 104 provided with insulating portions 106 at the upper and lower ends of a coiled conductor element 103 . The antenna element can slide in the helical element 104 and can be retracted into the housing 100 , and the retracted antenna element can be extended from the housing 100 .

Also, the helical element 104 is fixedly disposed in the protrusion on the upper end of the casing.

The state when the antenna element of this antenna is slid and extended is shown in (a) of FIG. 5(B). In this case, the signal generated from the signal source 102 inside the casing 100 is supplied to the power supply unit 105 through the matching circuit (MC) 101 . The power supply part 105 is electrically connected to the lower end of the helical element 104, and the helical element 104 is excited to vibrate. Since the helical element 104 and the coiled conductor element 103 are inductively coupled, the helical element 104 is excited, and thus the inductively coupled conductor element 103 is also excited.

Therefore, the antenna element and the helical element 104 are in working condition. Also, at this time, the insulating portion 106 formed at the lower end of the antenna element is positioned in the spiral element 104 .

Also, the state in which the antenna element is slid into the casing 100 is shown in (b) of FIG. 5(B). In this case, the signal generated from the signal source 102 in the casing 100 is supplied to the power supply unit 105 through the matching circuit (MC) 101, and the spiral element 104 connected to the power supply unit 105 is in an active state. At this time, the coiled conductor element 103 is housed in the housing 100 and is in a non-operating state.

In this case, the insulating portion 106 formed at the upper end of the antenna element is located in the helical element 104 so that the helical element 104 is not affected by the antenna element.

Next, the operation of the antenna will be described. In the conventional A-type antenna described above, when the antenna element is extended, the conductor element 103 and the helical element 104 are connected in parallel. At this time, the spiral element 104 plays a role equivalent to increasing the diameter of the conductor element 103 , and as a result, the frequency impedance characteristic exhibits a wider frequency band than that of a single conductor element 103 . At this time, the characteristics of frequency and voltage standing wave ratio (VSWR) are shown in Fig. 3(a) type A, because the resonant frequency of the helical element 104 and the conductor element 103 are set to be the same, so there is only a single resonance characteristic.

Also, in the existing A-type antenna, when the antenna element is retracted, only the helical element 104 works to form an L-C series resonant antenna. Therefore, the characteristics of frequency and voltage standing wave ratio (VSWR) at this time have only single resonance characteristics as shown in Figure 3 (b) A and B types.

In the conventional B-type antenna described above, when the antenna element is extended, the helical element 104 is connected to the feeder. At this time, the spiral element 104 is inductively coupled to the conductive element 103 in the unpowered state, and the conductive element 103 is excited at a high frequency. The characteristics of frequency and voltage standing wave ratio (VSWR) at this time are shown in Fig. 3(a) type B. The resonant frequency of the helical element 104 and the conductor element 103 are set to be the same, so there is only a single resonance characteristic.

Also, in the existing B-type antenna, when the antenna element is retracted, only the helical element 104 works to form an L-C series resonant antenna. Therefore, the frequency and voltage standing wave ratio (VSWR) characteristics at this time have only single resonance characteristics as shown in Figure 3(b) A and B types.

In the mobile phone, as shown on the frequency axis of FIG. 3, the transmission frequency band of the mobile station and the reception frequency band of the mobile station are allocated to different frequency bands. Therefore, the antenna of the portable telephone must have the characteristics of covering the transmission frequency band and the reception frequency band.

However, as shown in Fig. 3, the conventional A-type and B-type antennas have a problem that they cannot cover the characteristics suitable for the transmission frequency band and the reception frequency band because they both have single-resonance characteristics when they are extended and retracted. .

Therefore, an object of the present invention is to provide an antenna capable of covering a transmission frequency band and a reception frequency band assigned to different frequency bands when extended and retracted.

In order to achieve the above object, the antenna of the present invention is an antenna composed of an antenna element and a helical element that is connected with an upper conductor after being separated by an insulating part on the upper part of the conductor element, and the antenna element can be stretched freely in the helical antenna. When the antenna element is in an extended state, the lower end of the antenna element is in a power supply state; when the antenna element is in a retracted state, the upper end of the helical element is connected to the upper end of the upper conductor, At the same time, the lower end of the upper conductor is in a power supply state.

Also, in the antenna, the antenna element can slide freely in the support conductor connected to the circuit in the casing, and when the antenna element is in an extended state, the lower end of the antenna element is in contact with the support conductor , when the antenna element is in the retracted state, the lower end of the upper conductor is connected to the support conductor. Furthermore, the antenna element and the helical element operate as a dual resonant antenna when the antenna element is extended and retracted.

If the antenna of the present invention is used, because the antenna composed of the antenna element and the helical element becomes a dual-resonance antenna, so when extending and retracting, the antenna can obtain the transmitting frequency band and receiving frequency band that can cover and distribute in different frequency bands. characteristics of the frequency band.

The accompanying drawings are briefly described below.

Fig. 1 (a) is a schematic diagram showing the structure of an embodiment of the antenna of the present invention when it is extended; Fig. 1 (b) is a schematic diagram showing the structure of an embodiment of the antenna of the present invention when it is retracted.

Fig. 2 (a) is a diagram showing an example of the detailed structure of an embodiment of the antenna of the present invention when it is extended; Fig. 2 (b) is a diagram showing an example of the detailed structure of an embodiment of the antenna of the present invention when it is retracted.

Fig. 3 (a) is to represent the frequency and voltage standing wave ratio (VSWR) characteristic diagram of antenna of the present invention and existing antenna when elongating; Fig. 3 (b) is to represent antenna of the present invention and existing antenna when retracting Frequency vs. Voltage Standing Wave Ratio (VSWR) characteristic graph.

Fig. 4 is a diagram showing another detailed structural example of an embodiment of the antenna of the present invention.

FIG. 5(a) is a schematic diagram showing the structure of a conventional A-type antenna; FIG. 5(b) is a schematic diagram showing the structure of a conventional B-type antenna.

In order to explain this invention in detail, it demonstrates based on drawing.

Fig. 1(a), (b) shows the outline of the structure of an embodiment of the antenna of the present invention. In Fig. 1 (a), (b), the antenna is made up of the antenna element and the helical element 4 which are connected with the upper conductor 6 after being separated by an insulating part 8 on the conductor element 3 .

In this antenna, the antenna element can slide in the helical element 4 and can freely expand and contract from the housing 10. Figure 1(b) shows the state that the antenna element is received in the housing 10, and Figure 1(a) shows the antenna The state in which the element is extended from the housing 10. Moreover, the helical element 4 is fixedly disposed in the protrusion at the upper end of the casing 10 .

When the antenna element of the antenna is extended, a signal generated from the signal source 2 inside the housing 10 passes through the matching circuit (MC) 1 and is supplied to the power feeding unit 5 . The power supply part 5 is electrically connected to the lower end of the conductor element 3, and the conductor element 3 is in a working state. At this time, the helical element 4 is not connected to any place and is in a state of no power supply, and the helical element 4 is excited by high-frequency vibration through the high-frequency current of the conductor element 3 .

Also, the antenna element shown in Fig. 1(b) is in the state of being received in the casing 10, the signal generated by the signal source 2 in the casing 10 passes through the matching circuit (MC) 1, and supplies the power supply part 5, and the power supply part 5 is electrically connected with the lower end of the upper conductor 6 at the upper end of the antenna element. Furthermore, the upper end of the spiral element 4 is electrically connected at the connection point 7 at the upper end of the upper conductor 6 . Therefore, the helical element 4 is driven via the upper conductor 6 .

At this time, the conductor element 3 is in a non-operating state due to the insulation between the insulating portion 8 and the upper conductor 6 .

Next, the operation of the antenna of the present invention will be described. In the extended state of the antenna element, the conductive element 3 is in contact with the feeding part 5, and the conductive element 3 is excited. At this time, the high-frequency current of the helical element 4 passed through the conductor element 3 is excited by high frequency, and functions as a parasitic element. If the resonant frequency is set as the center frequency of the transmitting band of the mobile station, then the double resonance characteristic can be obtained in the frequency impedance characteristic.

That is to say, the characteristics of the frequency and voltage standing wave ratio (VSWR) of the antenna when extended, as shown in the present invention marked in Fig. characteristic.

Also, in the antenna of the present invention, in the state where the antenna element is retracted, the upper conductor 6 is in contact with the power supply part 5, and the upper end of the upper conductor 6 is in contact with the helical element 4. The overlapping part of type element 4 generates distributed capacitance. Therefore, by constituting an L-C parallel resonance circuit, a resonance frequency different from the natural resonance frequency of the upper conductor 6 can be obtained. Therefore, double resonance characteristics can be obtained.

That is to say, the characteristics of the frequency and voltage standing wave ratio (VSWR) of the antenna when it is retracted, as shown in the present invention marked in Fig. Double resonance characteristics of the receiving frequency band.

As mentioned above, the antenna of the present invention makes the resonant frequency of the conductor element 3 and the helical element 4 different, and when it is extended and retracted, it is in a double-resonant working state covering the transmission frequency band of the mobile station and the reception frequency band of the mobile station. Its detailed structure An example of Figure 2 (a), (b) shown.

FIG. 2( a ) is a diagram showing a state in which the antenna element is extended from the casing 10 . FIG. 2( b ) is a diagram showing the state in which the antenna element is housed in the housing 10 .

2 (a), (b), the antenna element shown in the tip of the insulating antenna cap 13 is formed, the antenna cap 13 extended downward extension portion of the lower outer periphery is fitted with the upper conductor 6 . The lower end of the extension part of the antenna cap 13 is protruded from the lower end of the upper conductor 6 , and the protruding extension part and the upper end of the conductor element 3 are press-formed as a whole.

The insulating tube 9 is inserted into the periphery of the conductor element 3, and the stop conductor 11 is embedded on the lower end insulating tube 9 of the conductor element 3, and the conductor element 3 and the stop conductor 11 become electrically connected.

This antenna element is inserted into the helical element 4 received in the outer protrusion of the housing 10 , and is freely slidably inserted into the bracket conductor 12 fixed on the housing 10 . The support conductor 12 is electrically connected to the matching circuit 1 , and the matching circuit 1 is connected to the signal source 2 .

The signal source 2 is equivalent to the terminal portion of the transmitting unit disposed in the casing 10 when the antenna transmits a signal;

As shown in Figure 2 (a), when the antenna element is elongated, the stop conductor 11 embedded in the lower end of the conductor element 3 is embedded in the support conductor 12 and is electrically connected, so the signal source 2 connected by the matching circuit 1 passes through The support conductor 12 and the stop conductor 11 are in contact with the conductor element 3 . At this time, due to the high-frequency current flowing into the conductive element 3, the unpowered spiral element 4, which is not connected to any place, becomes high-frequency coupled with the conductive element 3, and the spiral element 4 operates as a parasitic element.

Furthermore, due to the function of the insulating portion 8, the upper conductor 6 does not function as an antenna.

Also, as shown in Figure 2 (b), when the antenna element is received into the housing 10, the antenna cap 13 is punched with the outer protrusion of the housing 10, and the upper conductor 6 is inserted through the helical element 4, and its lower end is inserted into the spiral element 4. Insert in the support conductor 12 and become electrical connection. Therefore, the signal source 2 connected through the matching circuit 1 is connected to the lower end of the upper conductor 6 through the support conductor 12 . At this time, the upper end of the upper conductor 6 is in contact with the upper end of the helical element 4 , and a high-frequency current flows into the upper conductor 6 and the helical element 4 .

And, due to the effect of the insulating portion 8, the conductor element 3 is in a non-operating state. Thus, the overlapping portion of the upper conductor 6 and the helical element 4 constitutes an L-C parallel resonance circuit.

Next, Fig. 4 shows another example of the detailed structure of the antenna of the present invention. The antenna shown in this figure differs from the antenna structures shown in FIGS. 2( a ) and ( b ) in that the case 10 is not integrated but is formed independently. Since the operation form of the antenna is the same as the antenna shown in Fig. 2(a) and (b), detailed description thereof will be omitted, and the above-mentioned differences will be described.

Fig. 4 shows the extended state of the antenna element, the lower end of the conductor element 3 inserted into the insulating tube 9 is electrically connected to the stop conductor 11, and the lower end of the support conductor 12 is punched together. At this time, the holder conductor 12 is in contact with the conductor element 3 , and the conductor element 3 is in contact with the matching circuit 1 and the like built in the housing 10 .

The unpowered spiral element 4 that is coupled with the conductor element 3 by the high-frequency current flowing into the conductor element 3 is housed in a spiral element protective case 14 made of resin or the like. The spiral component protection sleeve 14 is fixed on the upper part of the support conductor 12 .

When mounting the antenna configured in this way on the case 10, it can be mounted on the case 10 by using the mounting screw portion 12-1 formed on the lower portion of the holder conductor 12.

Also, in the above-mentioned antenna of the present invention, because the conductor element 3 is made of an elastic material, the conductor element 3 wrapped by the insulating tube 9 has flexibility, even if the elongated antenna element collides with an obstacle, it can prevent Broken damage to the antenna element.

Moreover, when extending and retracting, the working mode of the antenna can be set to any size from about 1/4 wavelength to about 1/2 wavelength. In this case, the matching circuit 1 can be omitted when the condition is close to 1/4 wavelength.

As mentioned above, the antenna of the present invention is composed of different resonant frequencies of the conductor element and the resonant frequency of the helical element, so when the helical element becomes the state of no power supply, it functions as a parasitic element and is in a double-resonance working state; When the spiral element is energized, the overlapping part of the upper conductor and the spiral element forms an L-C parallel resonance circuit, which is in a double resonance working state.

Therefore, when the antenna of the present invention is extended and retracted, it can be used as a dual-resonance antenna that can cover both the mobile station transmission frequency band and the mobile station reception frequency band, and is suitable for portable devices, especially portable radiotelephones.

Declaration under Article 19 of the Treaty

Claim 1 clarifies that when the antenna element is extended and retracted, the antenna element and the helical element work simultaneously to work as a dual-resonance antenna.

None of the cited examples discloses an antenna operating as a dual resonant antenna.

Claims

Amendment in accordance with Article 19 of the Treaty

1. An antenna is composed of an antenna element and a helical element connected with an upper conductor after the upper part of the conductor element is separated by an insulating part, and it is characterized in that the antenna element can slide freely in the described helical antenna, When the antenna element is in the extended state, the lower end of the antenna element is in the power supply state, and the helical antenna in the non-power supply state is excited by the antenna element at high frequency, and the antenna element is in the retracted state. , the upper end of the helical element is connected to the upper end of the upper conductor whose lower end has been powered, and the overlapping part of the upper conductor and the helical antenna forms a parallel resonant circuit. Therefore, the antenna element is extended When retracted and retracted, the antenna element and the helical element work as a dual resonant antenna.

2. The antenna according to claim 1, characterized in that the antenna element can slide freely in the support conductor connected to the circuit in the housing, and when the antenna element is in an extended state, the lower end of the antenna element is in contact with the The support conductor is connected, and the lower end of the upper conductor is connected to the support conductor when the antenna element is in a retracted state.

Claims (3)

1. antenna, form by the antenna element and the spiral type element that are connected to upper conductor on the top of conductor element after with insulation division, it is characterized in that described antenna element can stretch in described helical antenna freely slides, described antenna element is when elongation state, the bottom of this antenna element becomes power supply state, described antenna element is when takeing in state, and the upper end of described spiral type element is connected with the upper end of described upper conductor, and the lower end of described upper conductor becomes power supply state.

2. antenna according to claim 1, it is characterized in that to be free to slide in the support conductor that links to each other with circuit of described antenna element in housing, described antenna element is when elongation state, the lower end of this antenna element and described support conductor join, described antenna element is when takeing in state, and the lower end of described upper conductor and described support conductor join.

3. antenna according to claim 1 and 2 is characterized in that antenna element in when elongation with when takeing in, and described antenna element and described spiral type element are worked as the double resonance antenna.

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