JPS6143805A - Phased array radar equipment - Google Patents

Abstract

PURPOSE:To attain detection and correction of the phase shift error of an antenna module by providing a means adjusting the phase shift amount of a reference signal phase shifter so that the difference between the proper phase of a high frequency signal and the phase of the reference signal is constant. CONSTITUTION:A part of a transmission signal extracted from a directional coupler 7 is given to a phase detector 16 via a high frequency switch 8 as a monitor signal 108 and subjects to phase detection by the reference signal 118 given with a proper phase shift by a phase shifter 18. In this case, a signal the same as the phase control signal given to the phase shifter 2 is given to the phase shifter 18 so as to make a phase detection voltage 116 constant when no phase error exists in the antenna module. That is, the phase shifters 2, 18 shift the phase of the input signal by the same amount and when the phase shift amount of the antenna module is proper, the phase difference between the inputs signals 108 and 118 of the phase detector 16 is kept constant regardless of the phase shift amount and then the phase detected voltage 116 is made constant.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a phase P-play radar device comprising a plurality of antenna elements.

(Prior Art) FIG. 2 is a block diagram showing a conventional phase r array radar device. This phased array radar device includes a phase shifter 2, a transmission/reception switch 3, a transmission amplifier 4,
receiving amplifier 5, circulator 6, directional coupler 7,
A plurality of antenna modules each including a high frequency switch 8 and an antenna element 9 are provided. This phased array radar device controls the phase of the high frequency signal supplied to the antenna element 9 in the antenna module, radiates the high frequency signal as a radio wave from the antenna element 9, and combines the radio waves in the air to form one antenna beam. The antenna beam is directed in a direction according to the phase control. In this radar device, in order to obtain the required directivity characteristics, it is essential to detect and correct the phase shift error of each antenna module. More specifically, the phase shift error of the antenna module is the difference between the appropriate phase shift amount set in the antenna module and the phase shift amount that actually occurs.

The conventional phased array radar system of FIG. 2 operates as follows. A part of the high frequency signal output from the signal source 13 is passed through the directional coupler 12 to the phase detector 16.
Most of the signal passes through the circulator 11 and the power divider/synthesizer 1 and is guided to each antenna module. In the antenna module, after a phase shifter 2 gives an appropriate phase change to form a predetermined antenna beam, it passes through a transmitter/receiver switcher 3, is amplified to the required power by a transmitter amplifier 4, and then is sent to a circulator. 6 to the directional coupler 7
sent to. The directional coupler 7 extracts a portion of its output and sends it to the phase detector 16 as a monitor signal 108 via the high frequency switch 8, while the majority of the output is supplied to the antenna element 9.

The antenna element 9 radiates the received high frequency signal into space as a radio wave. The high frequency power radiated into space is reflected by the target and received again by the antenna element 9, and then sent to the directional coupler 7.
, circulator 6, receiving amplifier 5, transmitting/receiving switch 3,
Passes through phase shifter 2 and is combined in power by power divider/synthesizer 1,
circulator 1] and is sent to the receiver 10. In order to detect and correct the phase shift error of each antenna module, a part of the output of the signal source 13 taken out from the directional coupler 12 by turning on the high frequency switch 8 of the antenna module to be inspected is used as the reference signal 112. After phase detection is performed on a part of the transmission signal (monitor signal) 108 which is sent to the phase detector 16 and extracted from the directional coupler 7 , a phase detected voltage 116 is sent to the comparator circuit 15 . The allowable range voltage generation circuit 17 receives the allowable range signal 11 from the computer 14.
4b, the allowable range upper limit voltage 117a and lower limit voltage 1
17b is output. The comparator 15 outputs a phase detection voltage 116
is within the range of the upper limit voltage 117a and the lower voltage 117b, and when the phase detection voltage 116 is outside the range, the phase shift error signal 115 that indicates the stability as the voltage 116 is outside the range is determined. Output. The computer engineer 4 instructs the phase shifter 2 to correct the phase shift amount by the magnitude of the phase shift error represented by the phase shift error signal 115. In conventional phased array radar devices, phase shift errors in each antenna module are detected and corrected in this manner.

(Problem to be Solved by the Invention) Therefore, in the case of the configuration shown in FIG.
If the phase of the monitor signal 108 with respect to 2 is represented by φ, and the phase detection voltage 116 is represented by When the phase φ is detected from V, the measurement error of the phase φ becomes very large when the phase φ is close to m- and d. Furthermore, if there are phase errors, amplitude errors, temperature fluctuations in the phase shifter 2, temperature fluctuations in the phase detector 16, and fluctuations in the input level to the phase detector 16, the phase detector 1
Since the detection characteristics of the detector 6 become as shown in the characteristic curve A or C in FIG. 3, and the characteristic curve deviates from the one previously stored in the computer 14, there is a drawback that the detection error of the phase φ further increases.

Furthermore, since the phase detection characteristic is non-linear, in order to determine whether the antenna module is within the required phase shift error range, the upper limit voltage corresponding to the phase detection voltage 116 must be applied in the allowable range voltage generation circuit 17. 117& and the lower limit voltage 117b are required, and the negative feedback gain for so-called phase shift correction is not constant. Therefore, the configuration of the negative feedback circuit for phase shift correction, especially the allowable range voltage generation circuit 17, becomes complicated. In addition, if there is a uniform variation (for example, temperature variation) in all antenna modules, even if the phase shift amount of phase shifter 2 is not adjusted, the antenna pattern will not be affected. Since a phase shift error is determined in the circuit 15 and a phase shift correction command is issued from the computer 14 to all phase shifters 2, the phase of the transmitted signal changes frequently, and the time correlation of the received signal at the receiver 10 often changes. This also has the drawback of making correlation processing of received signals difficult.

SUMMARY OF THE INVENTION An object of the present invention is to provide a phased play radar device that can accurately detect and correct phase shift errors in antenna modules and that has a simple circuit configuration.

(Means for Solving the Problems) The present invention provides a plurality of antenna elements to which high frequency signals are respectively supplied from a common signal source via different phase shifters, and a plurality of antenna elements each receiving a high frequency signal from a common signal source. A phased array radar device comprising: a phase detector that sequentially detects the phase by comparing it with a reference signal; and means for adjusting the amount of phase shift of the phase shifter based on the phase; a reference signal phase shifter that shifts the phase to generate the reference signal; and a reference signal phase shifter that shifts the phase of the reference signal so that the difference between the appropriate phase of the high frequency signal whose phase is detected and the phase of the reference signal is constant. The device is characterized in that it is provided with means for adjusting the amount of phase shift of the device.

(Function) In the present invention, when the amount of phase shift in the antenna module is an appropriate size as set, the phase of the high frequency signal sent from the antenna module to the phase detector to be phase detected and the reference signal. Adjust the phase shift amount of the reference signal phase shifter so that the phase difference is constant. In other words, when the phase of the high-frequency signal supplied to the antenna element whose phase is detected is appropriate, the reference signal is adjusted so that the phase difference between the high-frequency signal whose phase is detected and the reference signal is constant. Adjust the phase. Therefore, if the phase of the high-frequency signal supplied to the antenna element is appropriate for forming the required antenna directivity, when this phase is detected by the phase detector, the output voltage of the phase detector (phase detection voltage) becomes constant. Therefore, in the present invention, since the phase detector can always detect the phase in the straight line portion of the phase detection characteristic curve, the phase of the high frequency signal supplied to the antenna element and, by extension, the phase shift error of the antenna module can be accurately detected.

(Example) Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing one embodiment of the present invention.
13, 15 and 16 are the same as the apparatus shown in FIG. This is a reference signal phase shifter that generates a reference signal for the device 16.

Next, the operation of this embodiment will be explained. The operation of this device is the same as the conventional device shown in FIG. 2 except for the computer column 1 phase detector 16, the tolerance voltage generation circuit υ, and the phase shifter 18. A part of the transmission signal taken out from the directional coupler 7 is sent as a monitor signal 108 to the phase detector 16 via the high frequency switch 8, and a reference signal is given an appropriate amount of phase shift by the phase shifter 18. Phase detection is performed at 118. At this time, the same phase control signal as the phase control signal given to the phase shifter 2 is given to the phase shifter 18, and the phase detection voltage 1 when there is no phase shift error in the antenna module is given to the phase shifter 18.
16 is always constant. In other words, when the phase shifters 2 and 18 phase-shift the input signal by the same amount and the phase shift amount of the antenna module is appropriate, the input signal of the phase detector 16 is The phase difference between 108 and 118 is made constant, and thus the phase detection voltage 116 is made constant. Even if the phase shift amount of the antenna module is appropriate,
Since there is some amount of phase shift (offset phase shift amount) in the portion of the antenna module other than the phase shifter 2, the reference signal 11
8 and the monitor signal 108 are not necessarily in phase, and since the detection characteristics of the phase detector 16 are as shown in FIG. 3, the phase detection voltage 116 is usually not zero. However, since the amount of offset phase shift is small, the phase detector 16 is
It operates in the straight part of the characteristic curve.

In this way, when the amount of phase shift in the antenna module is the magnitude based on the command of the computer, that is, when it is appropriate, the phase detection voltage 116 is constant, so the upper limit set by the tolerance voltage generation circuit n The voltage 127a and the lower limit voltage 127b may be constant.

Therefore, the permissible range voltage generation circuit n does not need to receive a signal from the computer U indicating the permissible range. The comparison circuit 15 generates a phase shift error signal 115 when the phase error of the monitor signal 108 is not between 127b and 127b. Phase shift error signal 115 represents the phase error of monitor signal 108, ie, the phase shift error of the antenna module. Based on this phase shift error signal 115, the computer generates a phase shift signal 1 to be given to the phase shifter 2.
24a is corrected.

The computer instructs the phase shifter 18 by the phase shift signal 124b the amount of phase shift to be instructed to the phase shifter 2 when the phase shifter 2 shifts the phase according to the designed value.

In the embodiment shown in FIG. 1, the phase detector 16 operates on the linear portion of the excursion curve shown in FIG. Therefore, the phase shift error can be accurately corrected. In addition, in this embodiment, since the phase detection voltage 116 is constant regardless of the amount of phase shift of the antenna module, the gain of the negative feedback circuit for phase shift correction may be constant. The configuration of the setting circuit n can be simplified, and the circuit and program of the computer U can also be simplified. Furthermore, in this embodiment, phase shifters 2 and 1
8 have the same characteristics, even if temperature fluctuations, etc. occur uniformly in all phase shifters 2 and 18, no phase shift correction command is given to these phase shifters, so the receiver The time axis phase correlation in the received signals of 10 is maintained, and correlation processing of the received signals is easy.

In this embodiment, even if the phase shift amount of the phase shifter 2 is appropriate, the reference signal 118 and the monitor signal 108 do not necessarily have the same phase. Phase incest 18 and phase detector 1 that occur in the excluded part
6, the reference signal 118 and monitor signal 108 can always be in phase. Further, the same effect can be obtained by changing the phase shift signal 124b so that the same amount of offset phase shift is caused by the phase shifter 18 instead of the fixed phase shifter. In this way, by making the signals 11B and 108 in phase,
Since phase detection can be performed at the center of the linear portion of the characteristic curve shown in FIG. 3, the phase shift error of the antenna module can be detected most accurately.

(Effects of the Invention) According to the present invention, as explained in detail above, the phase shift error of the antenna module can be accurately detected and corrected.
Moreover, a phased array radar device with a simple circuit configuration can be provided.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of an embodiment of the present invention, FIG. 2 is a block diagram of a conventional phased array radar device, and FIG. 3 is a diagram showing detection characteristics of a phase detector. 1... Power divider/synthesizer, 2... Phase shifter, 3...
...Shipping'ttl) 'tj% 1. i... Transmission amplifier, 5... Receiving amplifier, 6... Circulator, 7... Directional coupler, 8... High frequency switch, 9
... Antenna element, 10... Receiver, 11... Circulator, 12... Directional coupler, 13... Signal source, 14... Computer, 15... Comparison circuit, 16...
...Phase detector, 17...Tolerance range voltage generation circuit, 1
8... Phase shifter, U... Calculator, Please... Voltage generation circuit for tolerance range. Figure 1 [

Claims (1)

[Claims] A plurality of antenna elements each receiving a high frequency signal from a common signal source via different phase shifters, and phase detection that sequentially detects the phase of the high frequency signal received by each of these antenna elements by comparing it with a reference signal. A phased array radar device comprising: a phase shifter; and means for adjusting a phase shift amount of the phase shifter based on the phase,
a reference signal phase shifter that shifts the phase of the high frequency signal to generate the reference signal; and a reference signal phase shifter that shifts the phase of the high frequency signal to generate the reference signal; and a reference signal phase shifter that shifts the phase of the high frequency signal to generate the reference signal; A phased array radar device comprising means for adjusting the amount of phase shift of a signal phase shifter.