JPH0611126B2 - Measuring device of cross polarization deterioration factor due to radio wave propagation path - Google Patents

Description

The present invention relates to a relative phase difference of polarization signals, which is a cause of cross polarization deterioration caused by passing through a radio wave propagation path including rainfall in microwave communication and the like. And a device for measuring relative attenuation.

As for the background art, by compensating for this from a signal in which the degree of discrimination of cross-polarized waves has deteriorated, it was possible to indirectly know the relative phase difference and relative attenuation of the polarized signal, from the opposite. It was not a direct measurement device, and these could not be measured accurately and easily.

[Problems to be Solved by the Invention]

An object of the present invention is to provide a device for accurately and easily measuring the relative phase difference and relative attenuation of polarized signals.

[Means for Solving the Problem] In the measuring apparatus for the factor of cross polarization deterioration due to a radio wave propagation path due to rainfall or the like according to the present invention, two frequencies of polarizations orthogonal to each other are transmitted from the transmission side of the measured radio wave propagation path. The measurement signal is transmitted to the receiving side of the measured radio wave propagation path, and the
A receiving antenna that receives a measurement signal of one frequency, and a power supply device including a polarization converter and a demultiplexer that separates the received measurement signal into a right-handed polarization component and a left-handed polarization component,
An amplitude / phase detector that obtains a phase difference and an amplitude ratio between the reception polarization components of each of the two frequencies from the right polarization component and the left polarization component separated from the measurement signal, and the phase difference An arithmetic circuit for performing a predetermined arithmetic operation on the amplitude ratio is provided.

[Action]

In the cross polarization deterioration factor measurement apparatus configured as described above, the measurement side of the measured radio wave propagation path is transmitted from the transmission side of the measured radio wave propagation path by transmitting the measurement signals of two frequencies of polarizations orthogonal to each other. The receiving side is provided with a receiving antenna for receiving the measurement signals of the above two frequencies, and a polarization converter and a demultiplexer for separating the received measurement signal into a right-handed polarization component and a left-handed polarization component. A power feeding device, and an amplitude / phase detector that obtains a phase difference and an amplitude ratio between the two reception polarization components of each of the two frequencies from the right-handed polarization component and the left-handed polarization component separated from the measurement signal. The relative phase difference Δφ, the relative attenuation Δα, and the inclination angle τ thereof, which are factors of polarization deterioration due to the radio wave propagation path, can be obtained by providing an arithmetic circuit that performs a predetermined arithmetic operation on the obtained phase difference and amplitude ratio.

〔Example〕

An embodiment of the present invention will be described with reference to the drawings. In FIG. 1, (1) is a transmitter, (2) is a transmitting antenna, and (3)
Is a receiving antenna, (9) is a power supply device that includes a polarization converter, a polarization demultiplexer, and the like, and demultiplexes a main polarization signal and a cross polarization signal,
(10) is an amplitude phase detector for detecting the amplitude ratio and phase difference between the main polarization signal and the cross polarization signal, and (11) is the main polarization signal and cross polarization obtained by the amplitude phase detector (10). FIG. 2 is an arithmetic circuit for detecting a relative phase difference and a relative attenuation, which are factors of the polarization deterioration of the system A, and their inclination angles based on the amplitude ratio and the phase difference between the signals. (1) (2) (3) (9)
3A and 3B are explanatory diagrams of a radio wave propagation path.

From the viewpoint of effective frequency use, a frequency reuse method using two orthogonal polarizations (for linear polarization, for example, horizontal polarization and vertical polarization, and for circular polarization, left-handed and right-handed circularly polarized waves) There is.
Compensation for deterioration of cross polarization discrimination due to non-uniformity such as rainfall in space is an essential condition for practical use of such a method in satellite communication systems. To do so, it is necessary to know the deterioration of cross-polarized waves and to quantitatively measure the deterioration due to rainfall. (23) collectively represents the polarization characteristics of the communication antenna and the transmission space in a matrix [C],
(24) shows the polarization characteristics of the receiving antenna polarization converter (9) in a matrix [K], (21) and (2)
2) are transmitters that send signals to the left-handed and right-handed terminals of the transmitting antenna, respectively. If the amplitudes are E _Li and E _Ri, respectively, the left-handed terminal (25) and right-handed terminal (2
The received signals E _LO and E _RO output to 6) are given by the following equation.

[K] and [C] respectively Here, K _LL is a coefficient in which the left-handed polarized wave is the output of the terminal (25), K _LR is a coefficient in which the left-handed polarized wave is the output of the terminal (26), and K _RL is a right-handed polarized wave the output of the terminal (25). Coefficient K _RR is a coefficient in which right-handed polarization is output from the terminal (26) C _LL is coefficient in which E _Li is converted to left-handed polarization C _LR is coefficient in which E _Li is converted to right-handed polarization C _RL is factor C _RR which E _Ri is converted into left-handed polarized wave is expressed by a factor E _Ri is converted into right-handed polarized wave E _LO = _{[K LL · C LL + K RL} · C LR ] E _Li + [K _LL・ C _RL + K _RL · C _RR ] E _Ri … (4) E _RO = [K _LR · C _LL + K _RR · C _LR ] E _Li + [K _LR · C _RL + K _RR · C _RR ] E _Ri … (5 ).

If only E _Li component of E _LO and E _RO is received and E _RO / _LO is calculated, Also, if only E _Ri component of E _LO and E _RO is received and is calculated, Becomes However, assuming that the polarization characteristics of the receiving antenna are ideal, K _LR = 0 and K _RL = 0.

Equations (6) and (7) indicate that the left-handed and right-handed polarization characteristics of the combined polarization characteristics of the transmission antenna and the transmission path can be detected, respectively.

Figure 3 shows the relative phase difference (DPS) exhibited by the transmission space; Δφ
And relative attenuation (D, A); the spatial plane of DΔα is τ from the X axis
If the polarization characteristic of the transmitting antenna is ideal, then [C] in FIG. 2 becomes the following equation.

Δα is D, A (dB) and Δφ is DPS (radian).

From the expressions (3), (6) and (8), when Cα1 · Cφ2 << 1 Further, from the expressions (3), (7) and (8), Cα2 · Cφ1 <<
When 1 When decomposed into

From equations (9) and (10), Δφ, τ and Δ
α can be obtained.

Δφ and τ are obtained by the following equation using the variables A1 and A2.

Similarly, the variables B1 and B2 are obtained by the following equation.

Δα and τ are obtained by the following equations using the variables B1 and B2.

Becomes

From the above, the relative phase difference Δφ is obtained from the equation (13), the relative attenuation Δα is obtained from the equation (17), and τ is obtained from the equations (14) to (1).
It can be seen from 8) that each can be found.

Next, Δφ in equation (13), Δα in equation (17) and equation (1)
4) Expression (9) which is an information element for obtaining τ in (18)
−1), formula (9-2), formula (10-1) and formula (10
A specific example of the measurement of -2) will be shown.

FIG. 4 is an example of a configuration of an amplitude / phase detector (10) for detecting an amplitude ratio and a phase difference between the main polarization signal and the cross polarization signal of FIG. In FIG. 4, (25) is a left-handed polarization component input terminal, (26) is a right-handed polarization component input terminal, (27) is a down converter, and (28) is a cross-polarization component signal as a main polarization. A phase detector which processes the signal of the component in the same phase, (29) is a phase detector which processes the signal of the cross polarization component in a state where the phase is different from the main polarization component by 90 °, (3
0) is a 90 ° phase shifter, and (31) to (34) are signal main power terminals.

As a result of signal processing in the circuit of FIG. 4, input terminals (25) (2
The input signal 6) is output from the output terminals (31) to (34) with the following contents.

(31) is the real part of Expression (9), that is, Expression (9-1). (32) is the imaginary part of equation (9), that is, equation (9-2). (33) is the real part of equation (10), that is, equation (10-1)
Is (34) is the imaginary part of equation (10), that is, equation (10-2)
Is Is output.

Next, the output terminals (31) to (34) of FIG.
The same numbers are connected to the terminals (31) to (34) of the circuit shown.

FIG. 5 shows an example of the configuration of an arithmetic circuit (11) for detecting the relative phase difference and the relative attenuation, which are the factors of the polarization deterioration, and the inclination angles thereof obtained by the amplitude / phase detector (10) of FIG. .

In FIG. 5, (35) executes equation (11) and A1
(36) executes the equation (12) to obtain A2, (37) executes the equation (15) to calculate B1, and (38) executes the equation (16). A subtracter for obtaining B2, (39) is based on the output A1 of the subtractor (35) and the output A2 of the adder (36), and the expressions (13) and (14)
An arithmetic unit for executing the arithmetic operation of the contents of (40) is an adder (3
An arithmetic unit for executing the arithmetic operations of the contents of equations (17) and (18) based on the output B1 of 7) and the output B2 of the subtractor (38),
(41) is a terminal for outputting a value Δφ proportional to the relative phase difference of the system A which is the calculation result of the calculator (39), and (42) is the relative position of the system A which is the calculation result of the calculator (39). A terminal that outputs a value 2τ that is proportional to the phase difference and the inclination angle of relative attenuation,
(43) is a terminal (44) that outputs a value 2 / 17.37Δα proportional to the relative damping of the system B, which is the calculation result of the calculator (40)
Is a terminal for outputting a value (2τ + π) proportional to the relative phase difference of the system B and the inclination angle of the relative attenuation, which is the calculation result of the calculator (40).

Either of the terminals (42) and (44) can be used as the calculation result proportional to the relative phase difference and the inclination angle of the relative attenuation.

From the above, the relative phase difference Δφ, the relative attenuation Δα, and the inclination angle τ thereof, which are the factors of cross polarization deterioration due to the radio wave propagation path, can be obtained.

〔The invention's effect〕

As described above, according to the present invention, the transmitting side of the measured radio wave propagation path transmits the measurement signals of two frequencies of polarizations orthogonal to each other, and the measuring side of the measured radio wave propagation path receives the above-mentioned 2
A receiving antenna that receives a measurement signal of one frequency, and a power supply device including a polarization converter and a demultiplexer that separates the received measurement signal into a right-handed polarization component and a left-handed polarization component,
An amplitude / phase detector for obtaining a phase difference and an amplitude ratio between the above reception two polarization components of each of the above two frequencies from the right polarization component and the left polarization component separated from the measurement signal, and the calculated position. By providing an arithmetic circuit for performing a predetermined arithmetic operation on the phase difference and the amplitude ratio, the relative phase difference Δφ, the relative attenuation Δα, and the inclination angle τ thereof, which are factors of cross polarization deterioration due to the radio wave propagation path.
Is accurate and easy to find.

[Brief description of drawings]

FIG. 1 is a block diagram showing a cross polarization deterioration factor measuring apparatus according to an embodiment of the present invention, FIG. 2 is a block diagram showing a transmitting / receiving antenna and a transmission space, and FIG. 3 is a characteristic diagram showing characteristics of the transmission space. 4 is a block diagram showing the amplitude / phase detector of FIG. 2,
FIG. 5 is a block diagram of the arithmetic circuit of FIG. In the figure, (1) ... transmitter, (2) ... transmission antenna,
(3) ... Receiving antenna, (9) ... Power feeding device, (10) ...
Amplitude / phase detector, (11) ... Arithmetic circuit, in the figure,
The same reference numerals indicate the same or corresponding parts.

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Akiyoshi Ogawa 2-3-2 Nishishinjuku, Shinjuku-ku, Tokyo International Telegraph and Telephone Corporation (72) Naoto Matsunaka 2-3-2 Nishishinjuku, Shinjuku-ku, Tokyo No. 80 International Telegraph and Telephone Corporation (72) Inventor Yoshihiko Yoshikawa Nakano 80, Minami-Shimizu, Amagasaki City, Hyogo Prefecture Mitsubishi Electric Corporation Communication Equipment Factory (56) Reference JP-A-53-88513 (JP, A) Special Kai 55-49052 (JP, A) Research on International Communications 1981 April No. 108 P. 87-119

Claims (1)

[Claims] 1. A measurement signal of two frequencies of mutually orthogonal polarized waves is transmitted from a transmission side of a measured radio wave propagation path, and a measurement signal of two frequencies is measured at a reception side of the measured radio wave propagation path. A receiving antenna that receives the signal, a power supply device that includes a polarization converter and a demultiplexer that separates the received measurement signal into a right-handed polarization component and a left-handed polarization component, and separates from the measurement signal. An amplitude / phase detector for obtaining a phase difference and an amplitude ratio between the two reception polarization components of each of the above two frequencies from the right-handed polarization component and the left-handed polarization component, and a predetermined value for the obtained phase difference and the amplitude ratio. Measurement of cross polarization deterioration factor by radio wave propagation path characterized in that relative phase difference, which is cross polarization deterioration factor, relative attenuation, and inclination angle of these are obtained by providing an arithmetic circuit for performing apparatus.