JPH04115179A - Radar - Google Patents

Abstract

PURPOSE:To obtain a signal in which a spurious is canceled by phase-detecting part of power of a transmission source signal and part of power of a power amplifier output signal, level-regulating it, phase-inverting it, and adding it to a video signal. CONSTITUTION:A detector 20 receives a detection signal 15 and a transmission signal 18, and phase-detects it. A level regulator 22 receives a detector output signal 21 from the detector 20, and equalizes the level of the output to that of a video signal 8 by an AGC signal. A power amplifier 3 receives the interference of noise from a power source, etc., adds a spurious to a power amplifier output signal 4, the signal 4 becomes a reflected wave 7 having a reflected wave by a moving target and a reflected wave by a ground surface having a spurious are mixed, and is output as a video signal 11. On the other hand, signals 15, 18 are detected by the detector 20 as a detector output signal 21, which is level-regulated by a regulator 22, output as a spurious video signal 23, and phase inverted by a phase inverter 24. Then, its differential signal 25 is added to the signal 22 to obtain a signal in which a spurious is canceled.

Description

[Detailed description of the invention] [Industrial application field] This invention relates to a radar device.

[Conventional technology]

FIG. 3 is a diagram showing an example of a conventional radar device. In FIG. 2, (11 is a transmission source signal generator that generates a transmission source signal, (2) is a transmission source signal, and (3) is this transmission source signal ( 2)
A power amplifier that amplifies the signal to the required transmission power.

(4) is a power amplifier output signal which is the output of this power amplifier (3); C5) is an antenna that irradiates the power amplifier output signal (4) to a moving target and receives a reflected signal from the moving target; (6) is the radiation wave irradiated from the antenna (5) to the moving target, (force is the reflected signal from the moving target, and (8) is the amplification of the reflected signal (7) to the required level and detection of all information necessary for signal processing. A receiver that outputs it as a video signal.

(9) is a transmitter/receiver switch that guides the power amplifier output signal (4) to the antenna (5) and the reflected wave (7) to the receiver (8), and αO is the received signal input to the receiver (8). , αD is a video signal which is an output signal of the receiver (8), and 02 is a signal processor that detects information necessary for the radar device from the video signal αB. Moreover, FIG. 4 is a diagram showing the signal in FIG. 3 in the frequency domain, and FIG. 4(a) is a diagram showing the transmission source signal (2
).

FIG. 4('b) shows the power amplifier output signal (4) and the radiation wave (6).

FIG. 4 <c>/i reflected wave (7) and received signal αG; FIG. 4(d) shows the video signal ON.

A conventional radar device is configured as described above, and the transmission source signal (2) of frequency foH2 generated by the transmission source signal generator (1) is amplified to the required power by the power amplifier (3), and then transmitted and received. It is guided to the neutral line (5) by the switch (9) and radiated into the air as a radiation wave (6). This radiation wave (6) is reflected by the ground surface and a moving target and becomes a reflected wave (7).

At this time, the reflected wave from the moving target causes a Doppler deviation fdHz'fc in frequency depending on the moving speed. Reflected wave (7)
is received by the antenna (5), passes through the transmitter/receiver switch (9), and is guided to the receiver (8) as a received signal 0■. The received signal Q[I is amplified by the receiver (8), subjected to 2-frequency conversion, 9-phase detection, and outputted to the signal processor O2 as a video signal 01), and 1 frequency f (signal of IH2 is detected as a reflected wave from a moving target). Ru.

[Problem to be solved by the invention]

Conventional radar equipment is configured as described above, so
When a power amplifier receives interference from power supply noise or noise from other equipment, spurious signals are superimposed on the output signal of the power amplifier, and as a result, spurious signals are superimposed on the radiated waves as well. The radiated waves are reflected by the ground surface and moving targets, but since the reflected waves from the ground surface have a high reflected power level, the spurious waves reflected from the ground surface are returned to the antenna with sufficient power to be received by the receiver. On the other hand, since the reflected power level of the reflected wave from a moving target is low, the spurious reflected wave from the moving target is reflected by the power that can be received by the receiver.
Only the reflected wave of the regular power amplifier output signal returns to the antenna with a power that can be received. Therefore, the received signal input to the receiver contains a mixture of spurious reflected waves from the ground surface and reflected waves of the regular power amplifier output signal from a moving target, and both are present in the video signal of the receiver. Mixed.

There was a problem in that it was difficult to identify them.

The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a radar device that outputs a video signal in which spurious noise generated by a power amplifier is eliminated.

[Means to solve the problem]

The radar device according to the present invention uses part of the power of the transmission source signal and part of the power of the power amplifier output signal.

After performing phase detection and level adjustment and inversion, it is added to the video signal of the receiver.

[Effect]

In this invention, part of the power of the transmission source signal and part of the power of the power amplifier output signal are phase-detected by a detector, and the spurious added by the power amplifier is superimposed on the video signal of the receiver. Converts to a detector output signal, which is a signal with the same frequency as the spurious. On the other hand, the receiver performs A G C (,6uto Ga1n
Control ) signal is output. This A GC(A
Is the power level of the detector output signal dependent on the autoGa1nC0ntro'l signal? After making the power level equal to that of the video signal, a single phase inverter inverts the multiple phases to obtain a difference signal, which is added to the video signal in an adder to eliminate spurious signals from the video signal.

C Example] FIG. 1 is a diagram showing an embodiment of the present invention.

fil, F2+, +31. (4L f5), (
61, C71, (81, C91, C1, αn.

α'2 is exactly the same as that of the conventional device. 01'i, a transmission source signal splitter that divides the power of the transmission source signal (2) into a signal; α is one output of the transmission source signal splitter Oe, which is input to the power amplifier (3). Power amplifier input signal.

OS is the detection signal that is the other output of the transmission source signal divider αJ, ae is the transmission signal divider that divides the power of the power amplifier output signal (4) into two signals, and aη is one of the transmission signal dividers 00. 0! is the output of the transmission wave which is input to the transmitter/receiver switch (9), 0& is the transmission signal which is the other output of the transmission signal distributor Oe, 0! l is AG C(
Auto Ga1n Control) signal, ■ is a detector that performs phase detection by inputting the detection signal +151 and the transmission signal OFj, all is the detector output signal which is the output signal of the detector ■, and ■ is the detector output signal ai+ is input. A level adjuster JIu device which makes the level of its output equal to the level of the video signal (8) by AGC (Auto Galn Control) signal αg, C! 31 is the spurious video signal that is the output of the level adjuster, C (a)
is a phase inverter that inverts the phase of spurious video signal O, 051 is a difference signal that is the output of the phase inverter, @ is an adder that adds video signal 01) and difference signal 05), @ is the output of adder @ is the adder output signal. Figure 2 is the first
This is a diagram showing signals of each part in the figure, and FIG. 2(a) is a transmission source signal (2).

Power amplifier input signal 04) and detection signal αe, FIG. 2(b) shows power amplifier output signal (4), transmitted wave αD, and transmitted signal αg, and FIG. 2(C) shows reflected signal (7) and received signal. 0α, Fig. 2(d) is the video signal o1), Fig. 2(e) is the detector output signal, Fig. 2(f) is the spurious video signal, Fig. 2(g) is the difference signal es, Figure ()1
) indicates the adder output signal τ.

In a radar device configured as described above.

The power amplifier (3) receives two frequencies f from the power supply and other equipment.
1Hz, f2H2 noise causes the power amplifier output signal (4) to have a frequency fO+fi H2I fO
+f2H2 spurious is added. This power amplifier output signal (4) is sent to the transmission signal divider ae and the transmission/reception switch (9).
is emitted into the air as a radiation wave (6) by the antenna (5), and is emitted by the moving target as fd II (z
It is reflected as a frequency of fo+f(IH2).

On the other hand, a part of the radiation wave (6) is reflected by the ground surface while maintaining the entire frequency of the radiation wave (6). Therefore, there are 9 reflected waves (7
) is the reflected wave of frequency fo+faHz from the moving target and the frequency fO+fi H2 as shown in Fig. 2(C).
There is a mixture of reflected waves from the ground surface with spurious signals of +fQ-1-f2H2. The reflected wave (7) is an antenna (5),
The received signal aυ passes through the transmitter/receiver switch (9) and the receiver (8
). The received signal 0α is amplified, 2-frequency converted, and 2-phase detected by the receiver (8), and output as a video signal αυ containing the signal f1H2/f2Hz shown in FIG. 2(d) and the reflected signal fdH2 from the moving target. . on the other hand.

The transmitted signal Og and the detected signal 05 are input to the detector ■, which detects the phase of the signal and generates a spurious signal f4 as shown in Fig. 2(e).
The detector output signal 011 includes Hz, f2Hz k.

This detector output signal is input to the 1211V level adjuster and output to A () C (Auto Ga1n Control
) Depending on the signal, the level of the spurious will be the same as that of the video signal C1.
The level of the spurious video signal t2 is adjusted to be the same as that of the spurious signal 1) and output as the spurious video signal t2. After the phase of the spurious video signal is inverted by a phase inverter C) 41, it is output as a difference signal 2 shown in FIG. 2(g).

The difference signal and the video signal a11 are added together in an adder (a) and inputted as an adder output signal (a) to a signal processor az.

〔Effect of the invention〕

As described above, this invention detects spurious components added by the power amplifier by phase-detecting part of the power of the transmission source signal and part of the power of the power amplifier output signal, and performs level adjustment. After the phase inversion process, the video signal of the receiver is added to the video signal, which has the effect of obtaining a video signal from which spurious signals have been eliminated.

[Brief explanation of the drawing]

FIG. 1 shows an embodiment of the present invention, and FIG.
FIG. 3 is a diagram showing a conventional radar device, and FIG. 4 is a diagram showing signals of each part in FIG. 3 in the frequency domain. In the figure, (1) is a transmission source signal generator, (2) is a transmission source signal, (3) is a power amplifier, and (4) is a power amplifier output signal. (5) is the antenna, (6) is the radiation wave, (7j is the reflected signal,
(8) is the receiver, (9) is the transmitter/receiver switch, aa is the received signal, all is the video signal, α2 is the signal processor, Q3
is a transmitting source signal splitter. 041 is the power amplifier input signal, α9 is the detection signal, αG is the transmission signal divider, 07) is the transmission wave, Og is the transmission signal,
(19 is A G C (Auto Ga1n Contr
ol ) signal, ■ is the detector, Ca1l is the detector output signal, ■ is the level adjuster, is the spurious level signal, (
2) is a phase inverter, and (c) is a difference signal. In addition. The same symbols in the figures indicate the same or equivalent parts.

Claims (1)

[Claims] A transmission source signal generator that generates a transmission source signal, a transmission source signal divider that receives and divides this transmission source signal into two and outputs a power amplifier input signal and a detection signal, and converts this power amplifier input signal to the required transmission power. a power amplifier that amplifies the output signal up to a power amplifier and outputs it as a power amplifier output signal, a transmission signal divider that divides this power amplifier output signal into two and outputs a transmission wave and a transmission signal, and a transmission signal divider that irradiates the transmission wave to a moving target and an antenna that receives the reflected signal from the antenna; a transmitting/receiving switch that switches between transmitting and receiving the transmitted wave and the reflected wave, guiding the transmitted wave to the antenna and outputting the reflected wave as a received signal to the receiver; Detects the information necessary for signal processing, outputs it as a video signal, and performs AGC (¥A¥
a receiver that outputs an auto\G\ain\C\ontrol) signal, a detector that performs phase detection on the transmitted signal and the detected signal and outputs it as a detector output signal, and a detector that outputs the output signal as a detector output signal. a level adjuster that adjusts the level to a constant level according to the level and outputs it as a level adjuster output signal; a phase inverter that receives this level adjuster output signal and outputs it as a difference signal after phase inversion; A radar device comprising: an adder that adds video signals and outputs the result as an adder output signal; and a signal processor that detects information necessary for the radar device from the adder output signal.