JPH11163954A - Polarized modulation method and demodulating device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize polarized modulation by means of a simple circuit by using an antenna which radiates two orthogonal and linear polarized waves in accordance with a signal input to two input/output terminals and giving difference in power feed phases to the two input/output terminals in accordance with binary digital signals. SOLUTION: An RF signal inputted from an input terminal 9 is distributed in two by a distributing circuit so as to be respectively inputted to a phase shifter 11. Phases are changed only by (ϕ1 and ϕ2) in the phase shifter 11 by a digital signal inputted from the input terminal 12 and the phase-shifted RF signals are inputted to the input/output terminals 13 and 13' of a microstrip antenna 14 so as to be radiated as a vertical polarized component and a horizontal polarized component. In this case, phase difference between the vertical polarized component and the horizontal polarized components is π/2 as against a digital signal '1' and a right hand circular polarization is radiated from the antenna 14. On the contrary, phase difference becomes -π/2 as against '0' and a left hand circular polarization is radiated from the antenna 14.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polarization modulation method for discretely changing a polarization plane or a polarization turning direction of an antenna according to a digital signal, and a demodulation device for demodulating a modulation signal by the polarization modulation method. About.

[0002]

2. Description of the Related Art Conventionally, a phase shift keying (PSK) method has been used for digital communication.

A conventional phase shift keying method will be described below with reference to FIG. FIG. 13 is a circuit diagram showing a modulation device to which a conventional shift keying method is applied. In FIG. 13, reference numerals 1 and 1 ′ denote input terminals of I and Q signals, 2, 2 ′ and 2 ″.
Is a mixer for modulation and up-conversion, 3, 3 'is a local oscillator (local signal source), 4 is a phase shifter, 5, 5'
Is a low-pass filter, 7 is an amplifier, and 8 is an output terminal of a transmission wave.

With this configuration, the I and Q signals are supplied to the mixer 2,
At 2 ', each is multiplied by the IF signal from the local oscillator 3 and combined to obtain four phase states. Thereafter, frequency conversion is performed by the mixer 2 ″, and amplification is performed by the amplifier 7 to obtain a transmission wave.

[0005]

However, in the conventional phase shift keying (PSK) method, for example, a four-phase PSK method is used.
In the case of SK, 1 in the baseband unit (not shown)
Π for data (symbols) of 1, 10, 01, 00
/ 4, 3π / 4, 5π / 4, and 7π / 4 are assigned. Therefore, a down-converter is required in a receiving circuit, and an up-converter and a modulator are used in a demodulator and a transmitting circuit. A plurality of mixers and a local signal source are required, and the circuit size is increased.

In this polarization modulation method, it is required to prevent an increase in circuit size, and in this demodulation device, it is required to demodulate a modulation signal by the polarization modulation method with a simple circuit.

It is an object of the present invention to provide a polarization modulation method which can be realized by a simple circuit, and a demodulation device which can demodulate a modulation signal by the polarization modulation method with a simple circuit.

[0008]

SUMMARY OF THE INVENTION In order to solve this problem, a polarization modulation method according to the present invention comprises two orthogonal input / output terminals, and orthogonally operates according to a signal input to the two input / output terminals. Using two linearly polarized antennas,
It has a configuration for providing a difference in the power supply phase to the two input / output terminals in accordance with the digital signal of the value.

Thus, a polarization modulation method which can be realized by a simple circuit is obtained. A demodulator according to the present invention for solving this problem is provided with an antenna for receiving two orthogonal linearly polarized waves and providing a phase difference between two orthogonal input / output terminals and a signal output terminal of the antenna. And a phase shifter.

As a result, a demodulation device capable of demodulating a modulation signal by the polarization modulation method with a simple circuit can be obtained.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention according to claim 1 of the present invention comprises two orthogonal input / output terminals and radiates two orthogonal linearly polarized waves in accordance with a signal input to the two input / output terminals. The difference between the power supply phases to the two input / output terminals is given in correspondence to the binary digital signal by using an antenna that performs a right-handed circular polarization and a left-handed It has the effect of emitting circularly polarized waves.

According to a second aspect of the present invention, there is provided an antenna comprising two orthogonal input / output terminals and radiating two orthogonal circularly polarized waves in response to a signal input to the two input / output terminals. In this case, a difference is given to the power supply phase to the antenna in accordance with the digital signal of (1), and has an effect that a vertically polarized wave and a horizontally polarized wave are radiated with respect to the digital signal of (1, 0).

According to a third aspect of the present invention, there is provided an antenna comprising two orthogonal input / output terminals and radiating two orthogonal circularly polarized waves in response to a signal input to the two input / output terminals. The power supply to the antenna is switched in response to the digital signal of (1), and has an effect that right-handed circularly polarized light and left-handed circularly polarized light are radiated for the digital signal of (1) and (0).

According to a fourth aspect of the present invention, there is provided an antenna having two orthogonal input / output terminals and radiating two orthogonal linearly polarized waves in response to a signal input to the two input / output terminals. In this case, the power supply to the antenna is switched in response to the digital signal of (1), and has an effect that a vertically polarized wave and a horizontally polarized wave are radiated with respect to the (1, 0) digital signal.

According to a fifth aspect of the present invention, there is provided an antenna having two orthogonal input / output terminals and radiating two orthogonal linearly polarized waves in response to a signal input to the two input / output terminals. An input signal of a different level is supplied to the input / output terminal for the multi-valued symbol indicated by the digital signal, and has an effect that the plane of polarization of the linear polarization is switched for the multi-valued symbol.

According to a sixth aspect of the present invention, there is provided an antenna for receiving two orthogonal linearly polarized waves, and an antenna for receiving two orthogonally polarized waves.
And a phase shifter that is arranged between the two input / output terminals and the signal output terminal to provide a phase difference, so that an output level corresponding to right-hand circular polarization and left-hand circular polarization can be obtained. Has an action.

According to a seventh aspect of the present invention, there is provided an antenna for receiving two orthogonal circularly polarized waves, and a phase shifter arranged between two orthogonal input / output terminals and a signal output terminal to provide a phase difference. And an output level corresponding to vertical polarization and horizontal polarization can be obtained.

The invention according to claim 8 is provided with an antenna having two orthogonal input / output terminals and an antenna for receiving two orthogonal circularly polarized waves. This has the effect that an output level corresponding to the polarization can be obtained.

According to a ninth aspect of the present invention, there is provided an antenna having two orthogonal input / output terminals and an antenna for receiving two orthogonal linearly polarized waves. This has the effect that a corresponding output level can be obtained.

According to a tenth aspect of the present invention, there is provided an antenna having two orthogonal input / output terminals and receiving two orthogonal linearly polarized waves, and detecting a reception signal output from the two input / output terminals of the antenna. And a subtraction circuit for calculating a difference between output signals of the two detectors, and N linearly polarized symbols corresponding to a multi-valued N symbol corresponding to the digital signal are provided. This has the effect that the modulated wave to which the wave is assigned is demodulated.

An eleventh aspect of the present invention provides an antenna having two orthogonal input / output terminals and receiving two orthogonal circularly polarized waves, and a receiving signal output from the two input / output terminals of the antenna. And a phase shifter for providing a phase difference, and has a function of demodulating a modulated wave to which N linearly polarized waves are assigned to a multilevel N symbol corresponding to a digital signal. Have.

According to a twelfth aspect of the present invention, there is provided an antenna for outputting a reception signal of a predetermined level with respect to a linearly polarized wave having a predetermined polarization plane. The modulation wave having N linearly polarized waves assigned to the symbol is demodulated.

Hereinafter, embodiments of the present invention will be described with reference to FIGS.
This will be described with reference to FIG. (Embodiment 1) FIG. 1 is a configuration diagram showing a modulation apparatus to which a polarization modulation method according to Embodiment 1 of the present invention is applied.
In FIG. 1, 9 is an RF signal input terminal, 10 is a distribution circuit for distributing an input RF signal into two, and 11 is two RF signals.
Phase shifter for changing the phase of the signal by φ1 and φ2, 12 is an input terminal to which a digital signal is input, and 13 and 13 'are inputs of a microstrip antenna 14 for emitting vertically polarized waves and horizontally polarized waves, which will be described later. Output terminal, 14 is input / output terminal 1
This is a microstrip antenna for radiating the signals input from 3, 13 'as vertically polarized waves and horizontally polarized waves, respectively. The phase shift amounts φ1 and φ2 in the phase shifter 11 change according to the digital signal input from the input terminal 12.
In FIG. 1, the radiating microstrip antenna 1 is shown.
Although the microstrip antenna is shown as 4, the form of the microstrip antenna 14 is not limited to the microstrip antenna, but may be any antenna that can radiate two orthogonal linearly polarized waves. In this case, there is an advantage that the microstrip antenna can be freely determined from a circuit configuration, a gain, an installation place, and the like.

A description will be given of a polarization modulation method in the modulation device configured as described above. The RF signal input from the input terminal 9 is split into two by the splitter 10 and input to the phase shifter 11, respectively. In the phase shifter 11, the phase is changed by (φ1, φ2) by the digital signal input from the input terminal 12, and the phase-shifted RF signal is input to the input / output terminals 13, 13 'of the microstrip antenna 14, It is radiated from the microstrip antenna 14 as a vertical polarization component and a horizontal polarization component. In the phase shifter 11, (φ1, φ2) = (0, π /
2), if (φ1, φ2) = (0, −π / 2) is set for “0”, the phase difference between the vertical polarization component and the horizontal polarization component for the digital signal “1” is π / 2, and a right-handed circularly polarized wave is radiated from the microstrip antenna 14. Conversely, for “0”, the phase difference between the direct polarization component and the horizontal polarization component is −π / 2, and a left-hand circularly polarized wave is radiated from the microstrip antenna 14.

As described above, according to the present embodiment, the phase of the RF signal is changed by (φ1, φ2) by the digital signal input from the input terminal 12 to radiate the vertically polarized wave and the horizontally polarized wave. Since the phase-shifted RF signals are input to the input / output terminals 13 and 13 'of the antenna, a simple circuit configuration of the microstrip antenna 14 radiating two orthogonal linearly polarized waves and the phase shifter 11 is provided. Thus, modulation using orthogonally identifiable signals of right-hand circular polarization and left-hand circular polarization becomes possible.

(Embodiment 2) FIG. 2 is a block diagram showing a modulation apparatus to which a polarization modulation method according to Embodiment 2 of the present invention is applied. 2, the input terminals 9, 12, the distribution circuit 10, and the phase shifter 11 are the same as those in FIG. Reference numerals 15 and 15 'denote input / output terminals for radiating right-handed and left-handed polarized waves, and 16 denotes a microstrip antenna for radiating right-handed and left-handed polarized waves. Although FIG. 1 shows a microstrip antenna as the radiating microstrip antenna 14, the form of the microstrip antenna 14 is not limited to the microstrip antenna, but may be any antenna that can radiate two orthogonal circularly polarized waves. in this case,
There is an advantage that an antenna can be freely determined from a circuit form, a gain, an installation place, and the like.

A description will be given of a polarization modulation method in the modulation device configured as described above. When the RF signal whose phase has been changed by the phase shifter 11 is input from the input / output terminals 15 and 15 'to the microstrip antenna 16, right-handed and left-handed circularly polarized components having different phases are emitted. .
In the phase shifter 11, (φ1,
φ2) = (0, π / 2), (φ1, φ2) = (0, -π /
By setting to give 2), two linearly polarized waves orthogonal to the digital signals "1" and "0" can be radiated.

As described above, according to the present embodiment, the phase of the RF signal is changed by (φ1, φ2) by the digital signal input from the input terminal 12, and the right-hand circular polarization and the left-hand circular polarization are changed. Input / output terminals 15, 15 of the antenna for radiating
′, The two orthogonal orthogonal polarized waves are formed by a simple circuit configuration of the microstrip antenna 16 and the phase shifter 11 that radiate two orthogonal circularly polarized waves. Modulation using such an identifiable signal.

(Embodiment 3) FIG. 3 is a block diagram showing a modulation apparatus to which a polarization modulation method according to Embodiment 3 of the present invention is applied. 3, the input terminals 9, 12, input / output terminals 15, 15 ', and microstrip antenna 16 are the same as those in FIG. Reference numeral 17 denotes a switch for switching the propagation path of the RF signal. The switch 17 selects a connection destination with the input terminal 9 to one of the input / output terminals 15 and 15 ′ of two orthogonal circularly polarized antennas in accordance with the digital signal input from the input terminal 12.

A description will be given of a polarization modulation method in the modulation device configured as described above. The path of the RF signal input from the input terminal 9 is switched by the switch 17 and input to the input / output terminal 15 or 15 ′. When input to input / output terminal 15, left-handed circularly polarized wave, input / output terminal 1
When input to 5 ', a right-handed circularly polarized wave is emitted.

As described above, according to the present embodiment, the input terminal 9 and the input / output terminal 15 or 15 'are connected in accordance with the digital signal input from the input terminal 12, so that the orthogonal With a simple circuit configuration of the microstrip antenna 16 that emits two circularly polarized waves and the switch 17, modulation using orthogonally identifiable signals of right-handed and left-handed circularly polarized waves can be performed.

(Embodiment 4) FIG. 4 is a block diagram showing a modulation apparatus to which a polarization modulation method according to Embodiment 4 of the present invention is applied. In FIG. 4, the input terminals 9, 12, input / output terminals 13, 13 ', switch 17, and microstrip antenna 14 are the same as those in FIGS. 1 and 3, and therefore are denoted by the same reference numerals and description thereof will be omitted. 4 is different from FIG. 3 in that the microstrip antenna is a microstrip antenna 14 that emits two orthogonal linearly polarized waves.

A description will be given of a polarization modulation method in the modulation device configured as described above. The path of the RF signal input from the input terminal 9 is switched by the switch 17 and input to the input / output terminal 13 or 13 ′. When input to the input / output terminal 13, horizontal polarization
, Vertical polarized waves are radiated.

As described above, according to the present embodiment, the input terminal 9 and the input / output terminal 13 or 13 'are connected in accordance with the digital signal input from the input terminal 12, so that the orthogonal With a simple circuit configuration of the microstrip antenna 14 that radiates two linearly polarized waves and the switch 17, it is possible to perform modulation using orthogonally identifiable signals of horizontal polarization and vertical polarization.

(Embodiment 5) FIG. 5 is a configuration diagram showing a demodulation device according to Embodiment 5 of the present invention. In FIG. 5, the phase shifter 11 is the same as that of FIG. , 13 and 13 ′ are input / output terminals of a microstrip antenna 14 described later, 14 is a microstrip antenna for receiving two orthogonal linearly polarized waves, and 18 is a composite of two outputs from the phase shifter 11 and outputs the combined output. Signal output terminal.

The operation of the demodulation device configured as described above will be described. When the right-handed or left-handed circular polarization corresponding to the digital signal is received by the microstrip antenna 14, the input / output terminals 13 and 13 '
Output signals having different phases. These are phase-changed by the phase shifter 11 and combined. When the right-handed circularly polarized wave corresponds to “1”, the phase shift amount (φ1, φ2) =
If (0, -π / 2) is set, the output is large when right-handed circularly polarized light is incident, and conversely, there is almost no output when left-handed circularly polarized light is incident. Become.

As described above, according to the present embodiment, the right-handed circularly polarized wave or the left-handed circularly polarized wave is received by the microstrip antenna 14, and the signals output from the input / output terminals 13 and 13 'are phase-shifted. 11, the phase of the digital signal is changed, so that the digital signal
With respect to the modulated wave to which the left-handed circularly polarized wave is assigned, the signal can be demodulated with a simple circuit configuration of the microstrip antenna 14 for receiving two orthogonal linearly polarized waves and the phase shifter 11.

(Embodiment 6) FIG. 6 is a block diagram showing a demodulator according to Embodiment 6 of the present invention. In FIG. 6, the phase shifter 11 and the signal output terminal 18 are the same as those in FIG. 15, 15
'Denotes an input / output terminal of a microstrip antenna 16 described later, and 16 denotes a microstrip antenna for receiving two orthogonal circularly polarized waves. 6 is different from FIG. 5 in that the microstrip antenna 16 is a microstrip antenna that receives two orthogonal circularly polarized waves.

The demodulator configured as described above will be described. When two orthogonal linearly polarized waves corresponding to digital signals are received by the microstrip antenna 16, signals having different phases are output to the input / output terminals 15 and 15 '. These are phase-changed by the phase shifter 11 and combined. The phase shift amount of the phase shifter 11 is (φ1, φ
2) = (0, -π / 2), the output increases for one linear polarization (for example, vertical polarization), but almost no output for the other linear polarization (for example, horizontal polarization). Can be performed.

As described above, according to the present embodiment, two linearly polarized waves are received by the microstrip antenna 16, and the signals output from the input / output terminals 15 and 15 ′ are changed in phase by the phase shifter 11. A microstrip antenna 16 for receiving two orthogonally polarized waves with respect to a modulated wave to which two linearly polarized waves orthogonal to a digital signal are assigned, and a phase shifter 1
The signal can be demodulated with the simple circuit configuration shown in FIG.

(Embodiment 7) FIG. 7 is a configuration diagram showing a demodulation device according to Embodiment 7 of the present invention. In FIG. 7, the input / output terminals 15, 15 'and the microstrip antenna 16 are the same as those in FIG.
Description is omitted. Reference numerals 19 and 20 denote signal output terminals for left-handed circularly polarized wave components and right-handed circularly polarized wave components, respectively.

The demodulation device configured as described above will be described. When two orthogonal circularly polarized waves corresponding to the digital signal are received by the microstrip antenna 16, an output is obtained at the signal output terminal 19 during reception of left-hand circular polarization, and the signal output terminal 20 is received at reception of right-hand circular polarization. Output is obtained. At this time, no output is obtained at the other signal output terminal. By comparing the output levels of the signal output terminals 19 and 20, it is possible to determine whether the right-handed circularly polarized wave or the left-handed circularly polarized wave has been received, and to demodulate the digital signal.

As described above, according to the present embodiment, an output is obtained at the signal output terminal 19 when receiving left-handed circularly polarized waves, and an output is obtained at the signal output terminal 20 when receiving right-handed circularly polarized waves. For a modulated wave to which two circularly polarized waves orthogonal to a signal are assigned, the signal can be demodulated with a simple circuit configuration of only the microstrip antenna 16 that receives two orthogonally circularly polarized waves.

(Eighth Embodiment) FIG. 8 is a block diagram showing a demodulation device according to an eighth embodiment of the present invention. 8, the input / output terminals 13, 13 'and the microstrip antenna 14 are the same as those in FIG.
Description is omitted. 21 and 22 are horizontal polarization components, respectively.
This is a signal output terminal for the vertically polarized wave component.

The demodulator configured as described above will be described. When two orthogonal linear polarizations corresponding to digital signals are received by the microstrip antenna 14, an output is obtained only at the signal output terminal 21 at the time of horizontal polarization reception, and only at the signal output terminal 22 at the time of vertical polarization reception. The output is obtained. At this time, almost no output is obtained at the other signal output terminal. By comparing the output levels of the signal output terminals 13 and 13 ', it is possible to determine which of the vertically polarized wave and the horizontally polarized wave has been received, and to demodulate the digital signal.

As described above, according to the present embodiment, an output is obtained only at the signal output terminal 21 at the time of receiving the horizontally polarized wave.
Since an output is obtained only at the signal output terminal 22 at the time of receiving vertically polarized waves, a micro wave receiving two orthogonal linearly polarized waves with respect to a modulated wave to which two linearly polarized waves orthogonal to a digital signal are assigned. The signal can be demodulated with a simple circuit configuration using only the strip antenna 14.

(Embodiment 9) FIG. 9 is a block diagram showing a modulation apparatus to which a polarization modulation method according to Embodiment 9 of the present invention is applied. In FIG. 9, input terminals 9, 12, input / output terminals 13, 13 ', and microstrip antenna 14 are the same as those in FIG. Reference numeral 23 denotes a variable amplifier whose gain can be adjusted, and the amplification amounts α and β change with respect to a multivalued digital signal or symbol input from the input terminal 12.

The polarization modulation method in the modulation device configured as described above will be described. After the RF signal input from the input terminal 9 is branched, the gain of the variable amplifier 23 is adjustable.
And are multiplied by α and β respectively. These signals are input to and radiated from a microstrip antenna 14 that emits two orthogonal linearly polarized waves via an input / output terminal 13 and an input / output terminal 13 '. In the variable amplifier 23, for example, in the case of four values, the amplification factor is set to (α,
By changing β) = (2,0), (3,1), (1,3), (0,2), the plane of polarization of the radiated radio wave changes discretely.

In the present embodiment, the variable amplifier 23 is arranged between the input terminal 9 and the input / output terminals 13 and 13 '. However, the variable amplifier 23 is used as a variable attenuator, and the amount of attenuation is represented by an amplification factor α. , Β.

As described above, according to the present embodiment, the amplification factors α and β of the variable amplifier 23 disposed between the input terminal 9 and the input / output terminals 13 and 13 ′ are input from the input terminal 12. Since it is changed corresponding to a multi-valued digital signal or symbol, a simple circuit configuration of the microstrip antenna 14 and the variable amplifier 23 that radiate two orthogonal linearly polarized waves allows the multi-valued digital signal or Modulation in which a discrete polarization plane is assigned to a symbol becomes possible.

(Embodiment 10) FIG. 10 is a block diagram showing a demodulation apparatus according to Embodiment 10 of the present invention, in which a modulated wave obtained by allocating a discrete polarization plane to a multilevel digital signal or symbol. 3 shows a demodulation device. In FIG. 10, input / output terminals 13 and 13 ', microstrip antenna 1
4. Since the signal output terminal 18 is the same as in FIG. 5, the same reference numerals are given and the description is omitted. Reference numerals 24 and 24 'denote detectors for linearly detecting the reception signal output from the microstrip antenna 14, and reference numeral 25 denotes a subtraction circuit for subtracting the detection signal output from the detector 24' from the detection signal output from the detector 24.

The demodulator constructed as described above will be described. When the modulated wave is received by the microstrip antenna 14, a horizontal polarization component and a vertical polarization component are obtained from the input / output terminals 13, 13 '. These two component outputs are linearly detected by the detectors 24 and 24 ', and then input to a subtraction circuit 25 for performing subtraction.
8, different output voltages are obtained depending on the polarization plane, and demodulation can be performed.

As described above, according to the present embodiment, the horizontal polarization component and the vertical polarization component obtained from the input / output terminals 13 and 13 'are linearly detected by the detectors 24 and 24' and then subtracted. The microstrip antenna 14 for receiving two orthogonal linearly polarized waves and the detector 2
With a simple circuit of 4, 24 'and the subtraction circuit 25, it is possible to demodulate a modulated wave in which a discrete polarization plane is assigned to a multi-valued digital signal or symbol.

(Embodiment 11) FIG. 11 is a block diagram showing a demodulator according to an eleventh embodiment of the present invention, in which a modulated wave in which a discrete polarization plane is assigned to a multilevel digital signal or symbol. Is shown. 11, a phase shifter 11, input / output terminals 15, 15 ', a microstrip antenna 16, and a signal output terminal 18 are the same as those in FIG.

The demodulation device configured as described above will be described. When the modulated wave is received by the microstrip antenna 16, a left-handed circularly polarized component and a right-handed circularly polarized component are obtained from the input / output terminals 15, 15 '. The phase shift amount (φ
When the signals are input to the phase shifter 11 fixed to (1, φ2) = (0, −π / 2) and combined after giving a phase difference, a difference occurs in the output level to the signal output terminal 18 due to a difference in the polarization plane. Yes, it can be demodulated.

As described above, according to the present embodiment, the left-handed circularly polarized wave component and the right-handed circularly polarized wave component output from the input / output terminals 15 and 15 'are phase-shifted (φ1, φ2) = (0 , -π / 2), the phase shifter 11 receives the phase difference and combines the signals after the phase shift. Therefore, the microstrip antenna 16 for receiving two orthogonal circularly polarized waves and the phase shifter 11 With this simple circuit, it is possible to demodulate a modulated wave in which a discrete polarization plane is assigned to a multilevel digital signal or symbol.

(Twelfth Embodiment) FIG. 12 is a block diagram showing a demodulator according to a twelfth embodiment of the present invention, in which a modulated wave in which a discrete polarization plane is assigned to a multilevel digital signal or symbol. Is shown. In FIG. 12, 1
8 is a signal output terminal, 26 is an input / output terminal of a microstrip antenna 27 described later, and 27 is a microstrip antenna for receiving one linearly polarized wave.

The demodulator configured as described above will be described. When a modulated wave is received by the microstrip antenna 27, only the polarization plane component of the microstrip antenna 27 of the received signal is output to the input / output terminal 26, and is output to the signal output terminal 18 by the polarization plane of the modulated wave. Level can be demodulated.

As described above, according to the present embodiment, only the polarization plane component of microstrip antenna 27 of the received signal is output to input / output terminal 26, so that the microstrip antenna receiving one linearly polarized wave With only 27 simple circuits, it is possible to demodulate a modulated wave in which a discrete polarization plane is assigned to a multilevel digital signal or symbol.

[0060]

As described above, according to the polarization modulation method of the first aspect of the present invention, two orthogonal input / output terminals are provided, and the two orthogonal input / output terminals are orthogonalized in accordance with a signal input to the two input / output terminals. By using an antenna that emits two linearly polarized waves and providing a difference in the power supply phase to the two input / output terminals in response to the binary digital signal, a right-handed circularly polarized signal is generated for the digital signals of 1 and 0. Since a wave and a left-handed circularly polarized wave can be radiated, an advantageous effect that polarization modulation can be realized by a simple circuit can be obtained.

According to the second aspect of the present invention, there is provided an antenna having two orthogonal input / output terminals and emitting two orthogonal circularly polarized waves in accordance with a signal input to the two input / output terminals, By providing a difference in the power supply phase to the antenna corresponding to the binary digital signal, it is possible to radiate the vertically polarized wave and the horizontally polarized wave with respect to the 1, 0 digital signal. An advantageous effect that wave modulation can be realized with a simple circuit is obtained.

According to the third aspect of the present invention, there is provided an antenna having two orthogonal input / output terminals and emitting two orthogonal circularly polarized waves in accordance with a signal input to the two input / output terminals. By switching the power supply to the antenna in accordance with the binary digital signal, it is possible to radiate right-handed and left-handed polarized waves with respect to the digital signals of 1 and 0. An advantageous effect that wave modulation can be realized with a simple circuit is obtained.

According to the fourth aspect of the present invention, an antenna having two orthogonal input / output terminals and emitting two orthogonal linearly polarized waves in response to a signal input to the two input / output terminals is used. By switching the power supply to the antenna corresponding to the binary digital signal, it is possible to radiate the vertically and horizontally polarized waves with respect to the 1 and 0 digital signals. An advantageous effect that it can be realized by a simple circuit is obtained.

According to the fifth aspect of the present invention, there is provided an antenna having two orthogonal input / output terminals and radiating two orthogonal linearly polarized waves in accordance with a signal input to the two input / output terminals. By supplying input signals of different levels to multi-valued symbols indicated by digital signals to the two input / output terminals, it is possible to switch the plane of polarization of linearly polarized light to multi-valued symbols. The advantageous effect that polarization modulation can be realized by a simple circuit is obtained.

According to the demodulation apparatus of the present invention, the antenna is arranged between two orthogonal input / output terminals and a signal output terminal of the antenna for receiving two orthogonal linearly polarized waves. By having a phase shifter for providing a phase difference, an output level corresponding to right-handed circular polarization and left-handed circular polarization can be obtained, so that a modulation signal by the polarization modulation method can be demodulated by a simple circuit. This has the advantageous effect of being able to perform.

According to the seventh aspect of the present invention, an antenna for receiving two orthogonal circularly polarized waves is provided between two orthogonal input / output terminals and a signal output terminal of the antenna to provide a phase difference. By having a phase shifter, vertical polarization,
Since an output level corresponding to horizontal polarization can be obtained, an advantageous effect that a modulation signal by the polarization modulation method can be demodulated by a simple circuit can be obtained.

According to the eighth aspect of the present invention, by providing an antenna having two orthogonal input / output terminals and receiving two orthogonal circular polarized waves,
Since an output level corresponding to left-hand circular polarization can be obtained, an advantageous effect that a modulation signal by the polarization modulation method can be demodulated by a simple circuit can be obtained.

According to the ninth aspect of the present invention, by providing an antenna having two orthogonal input / output terminals and receiving two orthogonal linear polarizations,
Since an output level corresponding to horizontal polarization can be obtained, an advantageous effect that a modulation signal by the polarization modulation method can be demodulated by a simple circuit can be obtained.

According to the tenth aspect of the present invention, there is provided an antenna having two orthogonal input / output terminals and receiving two orthogonal linear polarizations, and a reception signal output from the two input / output terminals of the antenna. And two detectors for detecting
By providing a subtraction circuit for calculating the difference between the output signals of the two detectors, it is possible to demodulate a modulated wave in which N linearly polarized waves are assigned to a multilevel N symbol corresponding to a digital signal. Therefore, there is an advantageous effect that a modulation signal of multi-level linear polarization by the polarization modulation method can be demodulated by a simple circuit.

According to the eleventh aspect, an antenna having two orthogonal input / output terminals and receiving two orthogonal circularly polarized waves, and a reception signal output from the two input / output terminals of the antenna By providing a phase shifter for providing a phase difference between the signals, it is possible to demodulate a modulated wave in which N linearly polarized waves are assigned to a multilevel N symbol corresponding to a digital signal. The advantageous effect that the modulation signal of multi-level linear polarization by the method can be demodulated with a simple circuit can be obtained.

According to the twelfth aspect of the present invention, a multilevel N symbol corresponding to a digital signal is provided by providing an antenna for outputting a reception signal of a predetermined level with respect to linear polarization of a predetermined polarization plane. Therefore, a modulated wave to which N linearly polarized waves are assigned can be demodulated, so that there is an advantageous effect that a modulation signal of a multilevel linearly polarized wave by the polarization modulation method can be demodulated by a simple circuit. can get.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing a modulation device to which a polarization modulation method according to a first embodiment of the present invention is applied;

FIG. 2 is a configuration diagram showing a modulation device to which a polarization modulation method according to a second embodiment of the present invention is applied.

FIG. 3 is a configuration diagram showing a modulation device to which a polarization modulation method according to a third embodiment of the present invention is applied.

FIG. 4 is a configuration diagram showing a modulation device to which a polarization modulation method according to a fourth embodiment of the present invention is applied.

FIG. 5 is a configuration diagram showing a demodulation device according to a fifth embodiment of the present invention.

FIG. 6 is a configuration diagram showing a demodulation device according to a sixth embodiment of the present invention.

FIG. 7 is a configuration diagram showing a demodulation device according to a seventh embodiment of the present invention.

FIG. 8 is a configuration diagram showing a demodulation device according to an eighth embodiment of the present invention.

FIG. 9 is a configuration diagram showing a modulation device to which a polarization modulation method according to a ninth embodiment of the present invention is applied.

FIG. 10 is a configuration diagram showing a demodulation device according to a tenth embodiment of the present invention.

FIG. 11 is a configuration diagram showing a demodulation device according to an eleventh embodiment of the present invention.

FIG. 12 is a configuration diagram illustrating a demodulation device according to a twelfth embodiment of the present invention.

FIG. 13 is a circuit diagram showing a modulation device to which a conventional polarization modulation method is applied.

[Explanation of symbols]

 9, 12 input terminal 10 distribution circuit 11 phase shifter 13, 13 ', 15, 15', 26 input / output terminal 14, 16, 27 microstrip antenna 17 switch 18, 19, 20, 21, 22 signal output terminal 23 variable Amplifier 24, 24 'Detector 25 Subtraction circuit

Claims (12)

[Claims] An input / output terminal includes two input / output terminals that are orthogonal to each other and are orthogonal to each other according to a signal input to the two input / output terminals.
A polarization modulation method using an antenna that radiates two linearly polarized waves, and providing a difference in a power supply phase to the two input / output terminals in response to a binary digital signal. 2. An apparatus comprising two input / output terminals which are orthogonal to each other, and wherein the two input / output terminals are orthogonal in accordance with a signal input to the two input / output terminals.
A polarization modulation method using an antenna that radiates two circularly polarized waves, and providing a difference in a power supply phase to the antenna in accordance with a binary digital signal. 3. An apparatus according to claim 1, further comprising: two input / output terminals which are orthogonal to each other, and wherein said two input / output terminals are orthogonal in response to a signal input to said two input / output terminals.
A polarization modulation method, comprising using an antenna that emits two circularly polarized waves and switching power supply to the antenna in accordance with a binary digital signal. 4. An apparatus comprising two input / output terminals which are orthogonal to each other, and wherein the two input / output terminals are orthogonal in accordance with a signal input to the two input / output terminals.
A polarization modulation method, comprising using an antenna that emits two linearly polarized waves, and switching power supply to the antenna in accordance with a binary digital signal. 5. An apparatus comprising two input / output terminals which are orthogonal to each other, and wherein said two input / output terminals are orthogonal in response to a signal input to said two input / output terminals.
A polarization modulation method using an antenna that radiates two linearly polarized waves and supplies input signals of different levels to multi-level symbols indicated by digital signals to the two input / output terminals. 6. An antenna for receiving two orthogonal linearly polarized waves, and a phase shifter disposed between two orthogonal input / output terminals and a signal output terminal of the antenna to provide a phase difference. Characteristic demodulator. 7. An antenna for receiving two orthogonal circularly polarized waves, and a phase shifter arranged between two orthogonal input / output terminals and a signal output terminal of the antenna to provide a phase difference. Characteristic demodulator. 8. A demodulator comprising two orthogonal input / output terminals and an antenna for receiving two orthogonal circularly polarized waves. 9. A demodulation device comprising two orthogonal input / output terminals and an antenna for receiving two orthogonal linearly polarized waves. 10. An antenna having two orthogonal input / output terminals and receiving two orthogonal linear polarizations, and two detectors for detecting a reception signal output from the two input / output terminals of the antenna. And a subtraction circuit for calculating a difference between output signals of the two detectors. 11. An antenna having two orthogonal input / output terminals and receiving two orthogonal circularly polarized waves, and a phase shift providing a phase difference between reception signals output from the two input / output terminals of the antenna. And a demodulator. 12. A demodulation device comprising an antenna for outputting a reception signal at a predetermined level with respect to linear polarization of a predetermined polarization plane.