JPS583339A - Selector for circular polarized electromagnetic wave - Google Patents

Abstract

PURPOSE:To simplify the switching of polarized waves, by picking up each of orthogonal polarized component, respectively and outputting either one of left or right rotary circular polarized wave electromagnetic waves through the change of one polarized component to the phase of another polarized component relatively by pi/2. CONSTITUTION:A circular polarized wave is inputted from one end of a circular waveguide 6, and polarized wave components E1 and E2 orthogonal to the inputted circular polarized waze are picked up from an output pickup section at the end. The polarized wave component E1 is directly inputted to a synthesizer 8 from the waveguide 6 and other polarized component E2 is applied to a + or -pi/2 phase modulator 7 and the phase is changed and applied to the synthesizer 8 by +pi/2 or -pi/2 with a control signal corresponding to the direction of polarized plane. The polarized components E1 and E2 from the waveguide 6 are applied to a Y-shaped directional coupling circuit 17 via a pi/2 phase shifter 16 with a microstrip line mounted on the insulation plate and applied to the circuit 17 via pi/2 phase modulator in which the polarized component E2 can be on/off controlled with an electrode 22 with microstrip lines 18 and 20 to simply switch the direction of the circular polarized electromagnetic waves.

Description

[Detailed description of the invention] The present invention relates to a circularly polarized radio wave selection device.

When a vertically polarized wave with an electric field in the vertical direction and a horizontally polarized wave with an electric field in the horizontal direction are combined, if the amplitudes of both are equal and the phases differ by 7, the amplitude and direction of the combined electric field will change as the wave progresses. However, when viewed through any cross section, it becomes circular. This is called circular polarization, and there are two types: right-handed polarized waves, in which the combined electric field rotates clockwise with respect to the direction of travel, and left-handed polarized waves, in which the combined electric field rotates counterclockwise. Since both of these can be transmitted and received without affecting each other, for example, in the SHF telepijo/broadcasting system using an artificial satellite, the broadcast waves of odd channel numbers are right-handed polarized waves, and the broadcast waves of even channel numbers are right-handed polarized waves. If the signal is left-handedly polarized, interference between adjacent channels can be prevented. Further, in the case of circularly polarized waves, when reflected, the rotating direction of the reflected wave is opposite to the rotating direction of the direct wave, so the reflected wave is not received on the receiving side, so there is an advantage that ghost-free reception can be performed.

As shown in FIG. 1A, as a device for generating circularly polarized waves, a rectangular-to-circular conversion waveguide / and an end at an angle of qso with respect to the electric field polarization plane of the rectangular TE10 mode and the circular TE/ mode are used. A configuration is known in which a dielectric body 3 having a wedge-shaped notch is arranged in a circular waveguide, and a circular polarization converter part is disposed in a circular waveguide. At the output of this rectangular-circular conversion waveguide, the electric field E
can be decomposed into a component E/ parallel to the dielectric 3 and a component E2 perpendicular to it, as shown in FIG. The phase velocity becomes slower, and the phase difference between the two becomes 1 at the output of the circular polarization converter.
becomes. Therefore, right-handed polarization is generated. Conversely, when a right-handed polarized wave is input from the circular polarization converter 2, a TE/θ mode radio wave is obtained from the rectangular waveguide of the waveguide l. Furthermore, if the dielectric material 3 is inserted parallel to one polarized wave component E2, the rectangular TE and θ mode inputs will not be left-handed polarized waves at the output of the circular polarization converter 2. , when a left-handed polarized wave is input from the circular polarization converter 1, a TEtθ mode radio wave is obtained from the rectangular waveguide of the waveguide l.

As another method for generating circularly polarized waves, as shown in FIG. There is something. The transmission direction of these rectangular waveguides a and pb is
As shown in FIG. λB, the dielectric material 3 of the circular polarization conversion unit
It is made to form an angle of . With the same operation as in the configuration shown in FIG. The radio wave becomes a left-handed polarized wave at the output of the circular polarization converter 2. Conversely, when right-handed or left-handed polarized waves are input from the circular waveguide side of the circular polarization converter V, the rectangular waveguide V
The output appears on a or ub.

It is possible to realize a circularly polarized radio wave selection device by using a device that generates circularly polarized waves as described above.

In the case of the configuration shown in FIG. 1, by mechanically rotating the angle of the circular polarization converter qo0, it is possible to switch and receive right-handed polarized waves and left-handed polarized waves. Furthermore, in the configuration shown in FIG. 2, the outputs of the rectangular waveguides Fa, <zb may be switched using an electrical switch.

However, unlike electrical switching, mechanical rotation does not allow instantaneous switching.

Further, in either case, there is a drawback that a circular polarization converter 2 is required, which is difficult to manufacture and adjust.

The present invention is a circularly polarized radio wave selection device that is applied to circularly polarized radio wave reception and can electrically switch instantly between right-handed and left-handed polarized waves. The objective is to realize a circularly polarized radio wave selection device that does not require a difficult circularly polarized wave converter.

FIG. 3 shows the basic configuration of this invention.

In Fig. 3, reference numeral 6 denotes a circular waveguide into which circularly polarized waves are input from one end, and by providing an output extraction section orthogonally to a difficult position from this termination, each output extraction section The orthogonal polarization component E/sE2 of the input circularly polarized wave is obtained from . Further, 7 indicates a phase modulator that gives a phase change of 10 or λ π m to a control signal according to the direction of the circularly polarized wave, and the detected one polarized wave component E2 is modulated by this phase modulator. The polarized wave component E is supplied to the combiner gK via the converter 7, is combined with the other polarized wave component E, and is taken out to the output terminal 9.

In the case of right-handed polarization, the orthogonal polarization components E/, E2 are equal to E with respect to El, as shown by solid lines in Figures A and B.
2 has a phase delay of Go. On the other hand, the polarization components E/ and E of the left-handed polarization have a phase lead of E2 relative to El, as shown by solid lines in FIGS. 5A and 5B. Therefore, if a phase change of 10- is given to the polarization component E2, as is clear from the waveform shown by the broken line in the square diagram B, for the right-handed polarization, the two polarizations supplied to the combiner g If the components are in phase, the left-handed polarized wave will be out of phase, and only the right-handed polarized wave will be output to the output terminal. On the contrary, if a phase change of m- is given to the polarized wave component E2, only the left-handed polarized wave is output, as is clear from the waveform shown by the broken line in FIG. SB.

FIGS. 6 and 7 respectively show configurations using a 01π phase modulator 10 and a 01π phase shifter // that causes a phase delay. In the configuration shown in FIG. 6, one polarization component E/ is supplied to the synthesizer via the phase shifter l/, and the other polarization component E2 is supplied to the synthesizer g via the phase modulator IO. supplying. If the amount of phase shift by this phase modulator 10 is zero,
A right-handed polarized wave is taken out at the output terminal 9, and if the phase shift 1 is π, a left-handed polarized wave appears at the output terminal 9.

In addition, in the case of the configuration shown in FIG.
0 and a phase shifter// to the synthesizer g.

Contrary to the configuration shown in FIG. 6, when the amount of phase shift by the phase modulator 10 is zero, a left-handed polarized wave is taken out, and when this is π, a right-handed polarized wave is taken out to the output terminal 9.

Compared to the case of thirteen-phase modulation, the o and π positions are Phase modulation simplifies the circuit configuration.

Examples of the present invention will be described below. In order to detect the orthogonal components E/ and E2 of the input circularly polarized wave, the configuration shown in FIG. 3 or FIG. 9 is used. The rows shown in FIG. 3 include rectangular waveguides t3a, 1. ? b
It was designed to provide a. In addition, in the example shown in FIG. 9, the other ends of the rectangular waveguides /Ja, /3b are short-circuited, and the coaxial line-waveguide converters /ua, /ub are connected to the rectangular waveguides /3a, /3b. They were attached to each of them.

Note that a microstripline-waveguide converter may be used instead of the coaxial line-waveguide converter.

If the orthogonal polarization components E/ and E2 of the circularly polarized waves detected in this way are shown in FIG.
a, /ffb. On the other hand, the polarized wave component E/ of λ is passed through a phase shifter/A consisting of a microstrip line/ having a length of - (λ is /wavelength) to a Y-shaped seven-directional combination circuit 17. Supplied. .

Also, microstrip line//rib is a conde/su, microstrip line//g, diode/9a
1 microstrip line 201 is connected to the coupling circuit 17 via a connector. Along with this, a - microstrip line 21 is provided between the microstrip line /l and λ of 20 via a diode /9b, and an electrode for controlling the on/off of the diodes /9a and /9b. 22 are provided.

λ When a positive DC voltage is applied to this electrode 22, the diode/? a is forward biased, diode /9b is reverse biased, diode /9a is turned off, diode /9b is turned off, and the polarized wave component E2 is passed through the microstrip line 2θ to the coupling circuit /? supplied to This is the case when the amount of phase shift of the polarization component E2 is zero. Also, if a negative DC voltage is applied to the electrode, the diode/? a and is supplied to the coupling circuit /7, and π
In addition, in the coupling circuit /7, the output sides of the - microstrip lines are commonly led out, and the input sides of the - microstrip lines are coupled by a resistor 23, and the two The configuration is such that each polarized wave component is added without being mixed into the other party's line system.

FIG. 11 shows another example of a circuit composed of microstrip lines, and the ol π phase modulator is the same as described above. However, one branch line directional coupler 2tI is installed on the output side.
is provided, and is configured to operate as a dual phase shifter.

Furthermore, a microwave circuit constructed from a waveguide other than a microstrip line may be used.

) An example of that case is shown in FIG. Each of the rectangular waveguides 2ta and 2b is excited by the polarization component E2, and the waveguide 2a has a phase shift of - length.
A reflection type 01π phase modulator 27, which is surrounded by a broken line, is provided in the waveguide 2b. This phase modulator 27 has a three-terminal circulator 2g, the first terminal of which is connected to a waveguide 2Sb, the second terminal of which is connected to a short plate 9, and a position between - and ground. A waveguide 31 having a diode 30 provided therein is connected thereto, and a waveguide 32 is connected to its third terminal. Then, when the diode 30 is turned off, reflection occurs in the diode 30 and the amount of phase shift becomes zero. Furthermore, when the diode 30 is turned off, the component reflected by the short plate 29 appears in the waveguide 32, and the amount of phase shift becomes π.

A Magic 1 circuit 33 is provided as a synthesizer on the output side, and a Nyoto plate is connected to the waveguide through which the polarized waves from the waveguides 26 and 32 flow together through a dummy resistor 3. It is connected.

In addition, when applying the above-described circularly polarized radio wave selection device to which this invention is applied to a receiver for SHF television broadcasting, the output of the microwave antenna is guided to an orthogonal component detection circuit, and the orthogonal components are detected by the above-mentioned phase detection circuit. A microwave circuitry consisting of a modulator and a combiner is supplied, and either the selected right-handed or left-handed polarization is supplied to a 5HF-UHF converter. The UHF output signal thus obtained is then guided to the indoor receiving unit.

As understood from the above description, according to the present invention,
It is possible to electrically switch between right-handed and left-handed polarized waves in an instant.3 In this case, switching can be done even if the phase modulator and its control circuit are separated, making it possible to use SHF television using artificial satellites. Even when the outdoor receiving unit includes a phase modulator, such as in a broadcasting receiver, switching operations can be easily performed indoors. Another advantage is that it does not require a circular polarization converter that is difficult and expensive to manufacture.

[Brief explanation of the drawing]

1 and 2 are configuration diagrams of an example of a conventional circularly polarized wave generator and other ν1], FIG. 3 is a configuration diagram showing an example of the basic configuration of the present invention, and FIGS. is a waveform diagram used for explaining this invention, and FIGS. 6 and 7 are waveform diagrams used for explaining this invention.
FIG. 8 and FIG. FIG. 12 is a circuit diagram of one embodiment and another embodiment of the present invention using a strip line, and FIG. 12 is a circuit diagram of still another embodiment of the invention using a waveguide. 6 is a circular waveguide, 7 is a two-phase modulator, g is a combiner, RI is an output terminal, IO is an O1π phase modulator, and // is a phase shifter.

Claims (1)

[Claims] Each of the orthogonal polarization components constituting a circularly polarized wave is extracted separately, and the phase of the other polarization component is changed by the amount of G relative to the phase of one of the polarization components. and the other polarized wave component whose phase has been changed relatively, and obtain either a right-handed circularly polarized radio wave or a left-handed circularly polarized radio wave depending on the relative phase change direction of i above. Nine circularly polarized radio wave selection devices.