JPH04190169A - Apparatus and method for measuring phase shifter module - Google Patents

Abstract

PURPOSE:To enable measurement of a phase shifter module of many systems by providing a network analyzer which measures the amplitude and phase of a synthesized signal on the basis of a reference signal. CONSTITUTION:A reference signal from a reference signal oscillator 4 is supplied to a transmission antenna 2. A signal emitted 2 is received by a reception element of each system of a phase shifter module 1 and given an appropriate amount of phase shift further, and then it is emitted toward a reception antenna 3 by an emission element of each of three systems. The signal received 3 is inputted to a synthesizer 5. Meanwhile, part of the reference signal from the oscillator 4 is taken out by couplers 6A and 6B, and the signal taken out by the coupler 6A is given appropriate amplitude and phase by a variable attenuator 7 and a phase shifter 8, and it is inputted to the synthesizer 5 and synthesized with the signal from the reception antenna 3. The signal taken out by the coupler 6B is inputted as a reference signal of a network analyzer 9, and based on this signal, the amplitude and phase of the signal synthesized 5 are measured 9.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an apparatus and method for measuring various characteristics of a phase shifter module constituting a secondary radiating section of a space-fed phased array antenna.

[Prior Art] A space-fed phased array antenna distributes power to each radiating element in space, so it is particularly difficult to use a feeding system for a planar phased array radar antenna that scans a pencil beam with a large number of radiating elements in two dimensions. Often used for brevity.

As shown in FIG. 6, the space-fed phased array antenna consists of a -order radiating section 101 and a secondary radiating section 102, and the secondary radiating section is composed of a large number of phase shifter modules 1. This phase shifter module 1 includes an element 111 that receives a signal fed from the -order radiator 101, a phase shifter 112 that provides a predetermined amount of phase shift depending on the beam scanning direction, and an element 113 that emits a signal into space. Consists of. The phase shifter 112 is generally a digital phase shifter using a PIN diode.

The signal controlling the phase shifter module l is sent to the antenna controller 1.
03 and is supplied to the phase shifter module 1 by serial data transmission to reduce the number of transmission cables. In addition to the above-mentioned high frequency system, the phase shifter module 1 is equipped with a control circuit including a decoder FL for control signals, a driver for operating a PIN diode phase shifter, and the like.

A method for measuring the phase shifter module having antennas at both ends will be described with reference to FIG. 7.

Measurements are performed in an anechoic chamber 11 separated into two chambers 13 and 14 by a shield plate 12 so that the radio waves from the transmitting antenna 2 are not received by the receiving antenna 3. First, a dummy module 1' in which the insertion loss and insertion phase of the transmission line 121 are known in advance and the characteristics of the elements 122 at both ends are completely adjusted is mounted at a predetermined position in the anechoic chamber 11.
The propagation loss and delay phase between the transmitting antenna 2 and the receiving antenna 3 are measured by the network analyzer 9, and the system is calibrated.

Next, the phase shifter module 1 to be measured is mounted at a predetermined position in the anechoic chamber 11, a control signal is given to the phase shifter, and one phase of the amplitude of each state is measured.

[Problem to be solved by the invention]

Conventionally, a phase shifter module has generally been manufactured as a single system consisting of one receiving element, one phase shifter and its control circuit, and one transmitting element. However, in recent years, the aperture size of antennas has become larger and the frequencies used have tended to become higher. For this reason, the number of phase shifter modules used has increased, and there has been a demand for miniaturization. Additionally, with the advancement of LSI technology, it has become possible to control multiple phase shifters with a single LSI, and from the standpoint of space efficiency and number of components, it has become possible to implement multiple high-frequency systems in one module. It is advantageous economically and in terms of manufacturing technology.

FIG. 8 shows an example of the configuration of a phase shifter module including three systems of high frequency circuits. Is the serial signal from the antenna controller 103 controlled? 11LS1104 converts it into a control code (parallel data) for the three phase shifters, and supplies it to the driver 105 to control each of the three systems IA, IB, and I.
Each phase shifter 112 of C is controlled respectively.

However, in a phase shifter module including such multi-system high-frequency circuits, if a conventional measurement device for a phase shifter module in which the high-frequency system is I system is used, unnecessary waves other than the system under test will also be transmitted to the receiving antenna 3. This creates a problem in that accurate measurements are difficult and impossible.

An object of the present invention is to provide a phase shifter module measuring device and a measuring method that make it possible to measure multiple phase shifter modules.

[Means to solve the problem]

The phase shifter module measurement device of the present invention includes a transmitting antenna that transmits signals to a plurality of receiving elements of the phase shifter module, and a receiving antenna that receives signals from a plurality of radiating elements of the phase shifter module. , a reference signal oscillator, means for variably attenuating and phase shifting a reference signal from the reference signal oscillator, a combiner for combining the attenuated and phase shifted reference signal with a signal from a receiving antenna; signal amplitude,
and a network analyzer that measures the phase based on the reference signal.

Further, in the method for measuring a phase shifter module of the present invention, a signal is transmitted to a plurality of receiving elements of the phase shifter module, a signal is received from a radiating element corresponding to each receiving element, and a signal included in the received signal is The phase of the signal of the system under test is adjusted to the reference vector, and the phase shifter of the system under test is sequentially shifted, and the insertion loss of the system under test is determined by numerical calculation from the scalar value of the composite signal.
Obtain a rough phase measurement value, cancel the signal other than the system under test with a separately generated cancellation signal, and sequentially shift the phase of the system under test to eliminate unnecessary signal components that remain uncancelled. The calculation is performed using the scalar value of the composite signal including the signal component and the rough measurement value, and the calculated unnecessary signal component is eliminated from the composite signal measurement value to obtain the desired measurement result.

〔Example〕

Next, the present invention will be explained with reference to the drawings.

FIG. 1 is a configuration diagram of a measuring device according to the present invention. In addition, the 6th
The directions of transmission and reception are reversed from left to right in FIGS. 8 through 8.

In FIG. 1, an anechoic chamber 11 is separated into two divided chambers 13 and 14 by a shield plate 12, and this shield plate 1
The phase shifter module 1 to be measured is mounted on 2. Furthermore, a transmitting antenna 2 is arranged in one chamber 13 of the anechoic chamber 11,
The receiving antenna 3 is arranged in the other chamber 14. The phase shifter module 1 here includes three systems IA, upper, middle, and lower.
It is equipped with an IB and an IC, and each system is composed of a receiving element 111, a phase shifter 112, and a radiating element 113, as shown in FIG.

A reference signal oscillator 4 is connected to the transmitting antenna 2, and a reference signal from the reference signal oscillator 4 is supplied to the transmitting antenna 2. The signal radiated from the transmitting antenna 2 is received by the receiving elements of each system of the phase shifter module 1,
After being given an appropriate amount of phase shift, it is radiated toward the receiving antenna 3 by the radiating elements of each of the three systems.

The signal received by the receiving antenna 3 is input to the combiner 5.

On the other hand, a part of the reference signal from the reference signal oscillator 4 is taken out by couplers 6A and 6B, respectively.
The signal extracted is given appropriate amplitude and phase by a variable attenuator 7 and a phase shifter 8, and then input to the synthesizer 5,
It is combined with the signal from the receiving antenna 3. In addition, the signal extracted by the coupler 6B is sent to the network analyzer 9
A network analyzer 9 measures the amplitude and phase of a composite signal that is input as a 0 reference signal and synthesized by the synthesizer 5 based on this signal.

In addition, in this example, the measurement system is automated.
The computer 10 sets the phase shift amount of each phase shifter of the phase shifter module 1, reads the measurement results of the network analyzer 9 and performs necessary control, and performs necessary settings of the variable attenuator 7 and the phase shifter 8.

Next, the measurement principle of the present invention will be explained.

Assume that the receiving antenna 3 receives a signal 24 in which signals from three systems of radiating elements are combined, as shown in FIG. 2(a), for example. At this time, the measured signal vector 23 and unnecessary vectors 21 and 22 exist. In order to eliminate the signal components of the unnecessary vectors 21 and 22, the approximate amplitude and phase of these signal components are determined, and a cancellation signal having a corresponding scalar amount and a phase inverted by 180° is generated. When the output from the receiving antenna 3 and the cancellation signal are combined, the measured vector 23 is generated as shown in FIG. 2(b).
The composite vector 26 of the component 25 that could not be completely canceled with
is obtained. Next, the component 25 that cannot be canceled out is determined, and this vector is subtracted from the composite vector 26 to determine the true vector to be measured.

Based on this principle, a method of measuring the phase shifter module in the example of FIG. 1 will be explained.

FIG. 3 shows the principle of rough measurement of the insertion loss 1 phase of each system of the phase shifter module. FIG. 3(a) shows a case where the set phase of each phase shifter in the phase shifter module is O. In FIG. 3(a), vector 31 is the reference signal output from phase shifter 8 in FIG.
represents a signal radiated from three systems of the phase shifter module 10 and received by the receiving antenna 3, and a vector 35 represents a combined signal output from the combiner 5.

The first step in this measurement is to roughly measure the amplitude and phase of each of the vectors 32 to 34. Therefore, after making the phases of the vectors 32 to 34 substantially coincide with the reference hector 31, the amplitude and phase of each of the vectors 32 to 34 are determined from the composite signal vector 35 by numerical calculation. Note that the phase shifter of the phase shifter module will be described hereinafter as a 4-bit phase shifter.

When the vector 34 is sequentially phase-shifted and subjected to 360° phase rotation, the scalar amount of the composite signal vector becomes a sine curve as shown in FIG. 3(b). System IC phase shifter 112
If the scalar amount of the composite vector 35 when the phases of are sequentially set is 5i (i=0 to 15), then the vectors 31,
2. Phase θ of vector 34 with respect to the composite vector of 33
1 and amplitude a1 are given by the following equations.

Based on the phase θ1 obtained by equation (1), the system IC
The phase shifter 112 of is advanced by the next state N and is fixed. This condition is represented by vector 34' in FIG. 3(C).

Phase θ for the composite vector of torques 31, 32, and 34'
2 and amplitude a2, vector 31°32.34'
The phase is advanced and fixed to match the phase of the resultant vector. This state is represented by vector 33' in FIG. 3(e).

Subsequently, the same processing is performed for the vector 32 as well.

FIG. 3(g) shows the state after the above series of processing is completed.

Next, the vectors 32' and 33' are fixed in the state shown in FIG. 3(g), and the vector 34' is 360
Rotate and perform the same processing as above to obtain vector 31.3
After finding the phase for the composite vector of 3' and 32',
Vector 31.33'.

It is fixed in accordance with the phase of the composite vector of 32'.

This is shown in FIG. 3(h).

The above processing is also performed for vectors 32' to 33'.

By repeating the above process several times, the phases θ1 to θ3 and amplitudes a, to a3 of the signals radiated from each radiating element with respect to the reference vector 31 are determined. Here, the upper and lower systems IA of the phase shifter module 1.

Regarding the IC, the propagation loss, delay phase amount, pattern loss of the elements of the phase shifter module, and pattern loss of the transmitting/receiving antenna are different from the central system IB, so it is necessary to correct these amounts.

The insertion loss and phase obtained through the above processing can be obtained with considerably high accuracy if the phase shifter module is ideally realized. However, in reality, due to manufacturing errors, the insertion phase and insertion loss measurement errors for, for example, an X-band phase shifter module are each about ±0.3 dB, making it difficult to obtain satisfactory accuracy.

FIG. 4(a) shows that the phases of vectors 32 and 33 are adjusted to the reference vector, and the phase shifter 1 of the system IC of the phase shifter module 1 is
The state when the set phase of No. 12 is set to 0 is shown.

Approximate values of the scalar quantities of vectors 32 and 33 have been determined by the rough measurements described above. The amplitude of the reference signal taken out from the coupler 6A is attenuated by the variable attenuator 7, and the vector 3
After controlling it so that it almost matches the sum of the scalar quantities of 2.33, it is inverted by the phase shifter 8. The vector relationship in this state is shown in FIG. 4(b).

Generally, a step type variable attenuator is used; 32
．． Since the scalar quantity of the vector 33 uses the value obtained in the previous numerical calculation, there is an error, and the direction of the vector 32.33 does not completely match the reference vector because it is a digital phase shifter. Vector 32.
33 cannot be completely canceled out, and there is a residual vector 36 shown in FIG. 4(c).

Next, the amplitude and one phase of the residual vector 36 are determined.

As shown in FIG. 5, the vector 34 is sequentially rotated, and the scalar amount of the composite vector 37 with the residual vector 35 is measured by the network analyzer 9. The amplitude ac and phase θ of the residual vector 36 are determined by processing this measured value according to the above-mentioned equations (1) and (2). is required. The phase θ found here. As shown in FIG. 5, since this is the phase relative to the initial phase of the vector 34, the phase relative to the reference vector 31 is the sum of the initial phase value θ1 of the vector 34 obtained by the method described above.

Since the amplitude ac 5 phase θ and the amplitude θ 6 of the residual vector 36 have been determined, the amplitude 1 phase of the vector 34 can be determined by subtracting the residual vector from the measured value of the network analyzer, that is, the amplitude 7 phase amount of the composite vector 37. . Needless to say, during the processing described above, the phases of the vectors 32 and 33 are maintained in the direction of the reference vector 31.

By performing the above processing on vectors 32 and 33 and correcting the propagation path length difference, etc. mentioned above for the elements at both ends of the phase shifter module, it is possible to know the amplitude and phase characteristics for each set phase amount of each system. I can do it.

Incidentally, the measurement accuracy when the present invention was applied was an amplitude of ±0.15 dB and a phase of 1.5° in a phase shifter module including three X-band systems including manufacturing errors.

[Effects of the Invention] As explained above, the present invention aligns the phase of the received signal of the system other than the system under test with the reference vector, sequentially shifts the phase of the phase shifter of the system under test, and performs numerical calculation from the scalar value of the composite signal. The rough measurement values of insertion loss and phase of the system under test are obtained using The phase shifter is sequentially shifted, and the scalar value of the composite signal containing the unnecessary signal component and the rough measurement value are used for calculation by numerical calculation, and the obtained unnecessary component is subtracted from the composite signal measurement value to obtain the measurement result of the desired system. As a result, the electrical characteristics of each system of a phase shifter module including a plurality of high frequency systems can be measured with high precision.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the configuration of the measuring device of the present invention, FIGS. 2(a) and (b) are conceptual diagrams showing the principle for extracting only the signal under test in the present invention, and FIG. 3(a) 4(a) to 4(h) are conceptual diagrams showing the principle of rough measurement in the first stage of measurement in the present invention, and FIGS. 4(a) to 4(c) are vector diagrams showing a state in which only the signal to be measured is extracted in the present invention, Fig. 5 is a conceptual diagram showing the principle of precise measurement in the final stage of the present invention, Fig. 6 is a block diagram of a space-fed phased array antenna, Fig. 7 is a block diagram showing a conventional measuring device, and Fig. 8 is a block diagram showing the principle of precise measurement in the final stage of the present invention. FIG. 3 is a configuration diagram of a three-system integrated phase shifter module. DESCRIPTION OF SYMBOLS 1... Phase shifter module, IA, IB, IC... system, 2... Transmitting antenna, 3... Receiving antenna, 4...
...Reference signal oscillator, 5...Synthesizer, 6A, 6B...
・Coupler, 7... Variable attenuator, 8... Phase shifter, 9
...Network analyzer, 10...Computer, 11...Anechoic chamber, 12...Shield plate, 13
．． 14...chamber, 101...-next radiation part, 102...
- Secondary radiation section, 103... antenna controller, 104.
...Control 111Lsr, 105...Driver, 111.
...Receiving element, 112... Phase shifter, 113... Radiation element. Ward (0 0 school Figure 6 Figure 8 Figure 7

Claims (1)

[Claims] 1. Consisting of an element that receives a signal from a primary radiator that constitutes a space-fed phased array antenna, a phase shifter that provides a predetermined amount of phase shift, and an element that radiates a signal into space. In a device that measures various characteristics such as insertion loss, insertion phase, and set phase of a phase shifter module in which multiple systems are installed,
a transmitting antenna that transmits a signal to a receiving element of each system of the phase shifter module; a receiving antenna that receives a signal from a radiating element of each system of the phase shifter module; a reference signal oscillator; and a reference signal oscillator. means for variably attenuating and phase-shifting a reference signal from the receiving antenna; and a combiner for combining the attenuated and phase-shifted reference signal with a signal from the receiving antenna;
A measuring device for a phase shifter module, comprising: a network analyzer that measures the amplitude and phase of a synthesized signal based on the reference signal. 2. Send a signal to multiple receiving elements of the phase shifter module, receive the signal from the radiating element corresponding to each receiving element, and use the phase of the signal other than the system under test included in this received signal as a reference vector. The phase shifter of the system under test is sequentially shifted according to the scalar value of the composite signal, and rough measurement values of insertion loss and phase of the system under test are obtained by numerical calculation from the scalar value of the composite signal, and signals other than the system under test are generated separately. The phase shifter of the system to be measured is sequentially shifted for the unnecessary signal components remaining without being canceled by the signal, and the scalar value of the composite signal containing the unnecessary signal components and the rough measurement value are used to calculate the A method for measuring a phase shifter module in which the calculated unnecessary signal component is subtracted from the composite signal measurement value to obtain a desired measurement result.