JP3106606B2 - Phase shifter measurement circuit - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a phase shifter measuring circuit,
In particular, the present invention relates to a phase shifter measuring circuit for measuring an insertion loss and an insertion phase of a phase shifter used in an antenna module of a transmission type space feeding electronic scanning antenna.

[0002]

2. Description of the Related Art Heretofore, a circuit for measuring the insertion loss and the insertion phase of a phase shifter of the above-mentioned antenna module of a transmission type space-fed electronic scanning antenna comprising an antenna module having a plurality of inseparable systems of phase shifters of this kind has been disclosed. In order to determine the insertion loss and insertion phase of the signal of the phase shifter of the system under test from the composite signals from the multiple systems of phase shifters, the signal power from the system under test and the composite signal from systems other than the system under test Ratio to electric power D /
U affects the measurement accuracy. For this reason, the phase shift amounts of the phase shifters are set to be mutually inverted so as to minimize the combined signal power of the systems other than the system to be measured.

[0003]

This conventional phase shifter measuring circuit measures the amplitude and phase of a combined signal from a plurality of systems that cannot be separated, so that the signal power of a system to be measured and a system other than the system to be measured are measured. In order to increase the ratio D / U, the state is set such that the phase shift amounts of the phase shifters of the systems other than the measured system are likely to be reversed. However, since the actual insertion loss and insertion phase of the phase shifter have an insertion loss error and an insertion phase error with respect to the set value due to a manufacturing error, even if the phase shift amount of a system other than the system to be measured is set to be inverted. However, it is not possible to sufficiently reduce the combined power level of the systems other than the system to be measured, and the measurement accuracy is affected by the insertion loss error and the insertion phase error due to the manufacturing error. There was a problem that he could not be satisfied.

[0004] The present invention has been made in view of the above problems, and can significantly improve the signal power ratio between the system to be measured and a system other than the system to be measured, thereby improving the measurement accuracy of insertion loss and insertion phase. It is an object to provide a phase shifter measurement circuit that can be improved.

[0005]

SUMMARY OF THE INVENTION A phase shifter measuring circuit according to the present invention comprises a plurality of phase shifters in a transmission type space-fed electronic scanning antenna comprising an antenna module having a plurality of non-separable phase shifters. In the phase shifter measuring circuit for measuring the insertion loss and the insertion phase of the plurality of phase shifters,
Measuring means for measuring the amplitude and phase of the composite signal received from
Phase shift control for setting the amount of phase shift of the plurality of phase shifters
And a phase shift controller for controlling the amount of phase shift and the measurement.
The insertion loss and insertion phase of each system from the measurement results of the
Computing means for calculating, wherein the computing means is
And the phase shift amount of the system other than the measured system is set to 0.
From 360 to 360 degrees in a predetermined step
The measured system that measures the amplitude and phase of the signal and maximizes it
Set the amount of phase shift for systems other than
Change the phase amount from 0 ° to 360 ° in predetermined steps
Measure the amplitude and phase of the combined received signal at each step.
And the phase shift amount of the system other than the measured system is
The phase is set to be opposite to the phase
Predetermined phase shift amount of phase shifter of measurement system from 0 ° to 360 °
In each step to change the composite received signal in each step.
The amplitude and phase of the signal are measured, and the amplitude and phase of the combined signal and the maximum combined signal for each step in the phase shift state of a system other than the system under test that substantially maximizes the combined signal power are obtained. In the phase shift state of the system other than the system under measurement, which is in the opposite phase to the phase shift amount, the combined signal component other than the system under measurement is obtained from the average value of the amplitude and the phase of the combined signal for each step, and characterized in that the one in which is subtracted from the average value of the amplitude and phase of the composite signal for each step for calculating the insertion loss and insertion phase of each step of the phase shifter of the measured system.

[0006]

In the present invention, the phase shifter of the system to be measured is rotated by 0 ° to 360 ° in the phase shift state of the system other than the system to be measured so as to maximize the combined signal power from the plurality of phase shifters. When the phase shifter of the system to be measured is rotated by 0 ° to 360 ° in a phase shift state other than the system to be measured such that the phase of the combined signal is equal to the phase shift amount at which the maximum combined signal is obtained. The insertion loss and the phase shift of the phase shifter of the measured system are calculated from the average value with the combined signal. This makes it possible to increase the ratio between the signal power from the measured system and the combined signal power from sources other than the measured system, thereby improving the measurement accuracy.

[0007]

Next, an embodiment of the present invention will be described with reference to the accompanying drawings.

FIG. 1 is a diagram showing a configuration of a phase shifter measuring circuit according to an embodiment of the present invention. The embodiment shown in FIG. 1 is an example in which the number of antenna modules to be measured is three. That is, the phase shifter measuring circuit includes an antenna module 1 having systems a, b, and c, phase shifters 12a, 12b, and 12c each including a 4-bit digital phase shifter of systems a, b, and c. Table 12
Collector elements 10a, 10b, 10c and emitter element 11 connected to the input / output sides of a, 12b, 12c, respectively.
a, 11b, 11c, transmitting antenna 2, and receiving antenna 3
And The network analyzer 4 has R
A part of the RF reference signal input from the F signal generator 7 via the coupler 13 is compared with the RF signal input from the reception antenna 3 to measure the amplitude and phase of the signal input from the reception antenna 3. . The phase shift controller 5 sets each of the phase shifters 12a, 12b, and 12c of the 4-bit digital phase shifter to a predetermined state, that is, a predetermined phase shift amount. Further, the CPU 6
Controls the phase shift amount of the phase shift controller 5 and controls the network analyzer 4 to calculate the insertion loss and loss phase of each system a, b, c of the antenna module 1. RF
The signal generator 7 outputs a reference RF signal, and the anechoic box 8 connected to the network analyzer 4 via the coupler 13 separates the transmitting side and the receiving side in high frequency at the center, and The measurement section of the antenna module 1 can be attached to the section. Next, the operation of the phase shifter measurement circuit according to the present embodiment will be described in the following sections (1) to (10).

(1) The systems of the antenna modules to be measured are a, b and c, respectively, the system b at the center is the system to be measured, and the transmitting antenna 2 and the receiving antenna 3 are arranged to face each other.

(2) Fixing the state of the measured system b,
22. The phase shift amount of the system a and the system c is 0 ° to 360 °.
The amplitude and the phase of the received RF signal are measured by the network analyzer 4 by changing the phase shift controller 5 in 16 steps at intervals of 5 °.

(3) The CPU 6 searches for the maximum state of the system a and the system c in the amplitude measurement values of the item (2).

(4) The phase shift amounts of the systems a and c other than the system to be measured are set to the state searched in (3), and the phase shift amount of the system to be measured b is 22.5 ° from 0 ° to 360 °. Ticking 1
Variable by the phase shift controller 5 in 6 steps, each phase shift amount 0
°, 22.5 °, 45 °, ..., 337.5 °
The amplitude and phase of the received RF signal in the state are measured by the network analyzer 4.

(5) The CPU 6 calculates a state in which the phase shift amounts of the systems a and c other than the system to be measured are inverted by 180 ° with respect to the state searched in (3). The phase shift amounts of the phase shifters of the systems a and c are set to the above state, and the phase shift amount of the measured system b is set to 2 from 0 ° to 360 °.
Variable by the phase shift controller 5 in 16 steps in increments of 2.5 °, and each phase shift amount is 0 °, 22.5 °, 45 °,.
The amplitude and phase of the received RF signal in 16 states of 7.5 ° are measured by the network analyzer 4.

(6) The CPU 6 calculates an average value of the measured values of the amplitude and the phase measured in the item (4) and the measured values of the amplitude and the phase measured in the item (5), and based on the amplitude and the phase. This is represented by a complex number as shown in FIG.

In the complex plan view of FIG. 2, the center of the circle can be determined from the averaged measured values of any three points in 16 steps, so that the averaged measured values of three points (x1, y) are obtained.
1), (x2, y2), (x3, y3) from the center of the circle (x0,
y0) is calculated by the following equation (1). This center coordinate (x
The absolute value of the vector based on the amplitude and the phase indicated by (0, y0) is the level of the combined signal from a system other than the measured system.

[0016]

(Equation 1)

(7) The center (x0, y0) in the combination of three points other than the term (6) out of the 16 measurement points is determined (up to 16C3 = 560), and the average value [av (x
0), av (y0)] is calculated. Here, av () indicates the average value of the items enclosed in (). The center of the circle [av (x0), av (y0)] as the average value thus obtained is
5 shows an estimated value of a combined electric field by the systems a and c.

(8) The insertion loss for each state of the measured system b is obtained by the following equation (2).

[0019]

[Expression 2] Li = Route [(xi−x0) ² + (yi−y0) ² ] where Route [] is the square root of what is enclosed by [], and i = 1, 2,. .

(9) The insertion phase for each state of the measured system b is obtained by the following equation (3).

[0021]

## EQU3 ## Pi = tan ^-1 {(yi-y0) / (xi-x0)} where i = 1, 2,..., 15, 16.

(10) Next, when measuring other systems of the antenna module, the measurement is performed in the same manner as in the measurement procedures (1) to (9).

Thus, the insertion loss and the insertion phase of each system can be determined.

FIGS. 3 and 4 are graphs showing the effect of the present embodiment. The vertical axis shows the signal power ratio D / U between the system under test and the system other than the system under test. FIG. 4 shows a simulation result in the case of this embodiment. From FIGS. 3 and 4, the present embodiment has a D / D
U can improve by about 10 dB, so that the measurement accuracy is the amplitude δ
It is estimated that m = 0.6 dB and phase δm = 3.8 ° can be achieved.

[0025]

As described above, according to the present invention, in an antenna module having a plurality of systems in which a collector element and an emitter element are connected to the input / output terminals of a phase shifter, respectively, when all the systems cannot be separated, A combined signal obtained by rotating the phase shift amount of the measured system in a predetermined step from 0 ° to 360 ° in a phase shift state of a system other than the measured system such that the combined signal power of the system is maximized; In a phase shift state of a system other than the system under measurement such that the phase shift amount is opposite to the phase amount at which the maximum synthesized signal is obtained, the phase shift amount of the system under measurement is rotated in a predetermined step from 0 ° to 360 °. By averaging the amplitude and phase of the synthesized signal obtained as described above, the signal power ratio D / U between the system under test and the system other than the system under test can be significantly improved, and the insertion loss due to a manufacturing error of the phase shifter can be improved. Error and wrong insertion phase To reduce the influence on the measurement accuracy,
There is an effect that excellent measurement accuracy of the insertion loss and the insertion phase can be obtained.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a phase shifter measurement circuit according to an embodiment of the present invention.

FIG. 2 is a complex plan view showing a combined signal vector in the embodiment of FIG.

FIG. 3 is a diagram showing a conventional ratio of signal power from a system to be measured to composite signal power from a system other than the system to be measured.

FIG. 4 is a diagram showing a ratio of a signal power from a system to be measured and a combined signal power from a system other than the system to be measured in the present embodiment.

[Explanation of symbols]

 1, 9; antenna module 2: transmission antenna 3: reception antenna 4: network analyzer 5, 5a; phase shift controller 6; CPU 7, RF signal generator 8, anechoic box 10, 10a, 10b, 10c; collector element 11 , 11a, 11b, 11c; Emitter elements 12, 12a, 12b, 12c;

Claims (1)

(57) [Claims] 1. A phase shifter measuring circuit for measuring an insertion loss and an insertion phase of a plurality of phase shifters in a transmission type space feeding electronic scanning antenna comprising an antenna module having a plurality of non-separable phase shifters . , Transfer of the plurality of systems
Measurement to measure the amplitude and phase of the composite signal received from the phaser.
Means for setting the phase shift amount of the plurality of phase shifters.
Controlling a phase shift amount of the phase controller and the phase shift controller;
From the measurement result of the measuring means, the insertion loss and insertion of each system
Calculation means for calculating the phase, wherein the calculation means
The phase shift amount of the measurement system is fixed, and the phase shift of systems other than the measured system is performed.
Rotate the amount from 0 ° to 360 ° in predetermined steps
Measure the amplitude and phase of the received signal and measure
Set the amount of phase shift for systems other than the fixed system, and
The phase shift of the detector is changed in a predetermined step from 0 ° to 360 °.
And the amplitude and position of the composite received signal in each step.
Phase and measure the amount of phase shift for systems other than the
Set so that the phase is opposite to the amount of phase shift at which the synthesized signal is obtained
Then, adjust the phase shift of the phase shifter of the measured system from 0 ° to 360 °.
To change in a given step and combine in each step
The amplitude and phase of the received signal are measured, and the amplitude and phase of the combined signal and the maximum combined signal at each step in the phase shift state of a system other than the system under test that substantially maximizes the combined signal power are obtained. In a phase shift state of a system other than the measured system, which is in a phase opposite to that of the measured phase shift amount, a synthesized signal component other than the measured system is obtained from the average value of the amplitude and the phase of the synthesized signal for each step in each step. It said phase shifter measurement, characterized in that subtracted from the average value of the amplitude and phase of the composite signal for each step is to calculate the insertion loss and insertion phase of each step of the phase shifter of the measurement system circuit.