JPH0654350B2 - Radar equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to an electronic scanning array radar device, in particular, a monopulse high precision measurement of the direction of arrival of an interference signal (azimuth angle, elevation angle) in parallel with the original target detection. The present invention relates to a radar device that bends.

[Conventional technology]

Typical examples of the electronic scanning array radar include a phase scanning array radar, a frequency scanning array radar, a phase / frequency compound scanning array radar, and the like.
Here, the phase scanning array radar apparatus having the configuration shown in FIG. 7 and performing the beam scanning shown in FIG. 2 will be described as an example, and the description will be given below.

FIG. 7 shows the direction of interference signal arrival (azimuth angle) in a conventional phase scanning array radar in which an array antenna element is arranged in a pair with a phase shifter in the vertical plane, and vertical plane electronic scanning and mechanical rotation in the horizontal plane are performed. Only) is shown.
In this figure, 1 is an array, 2 is a phase shifter group, 3 is a distribution circuit, 4 is a hybrid, 5 is an antenna drive circuit (A
Z), 6 is a phase shifter drive circuit, 7 is a beam control circuit, 8 is a transmitter, 9 is a reference signal generation circuit (A), 10 is a transmission / reception switcher, 11 is a high frequency amplification circuit, and 12 is a first mixing circuit. , 13
Is a second mixing circuit, 14 is an intermediate frequency amplifier circuit, 16 is a disturbance direction detection circuit (A), 17 is an information processing circuit, 18 is a display circuit, and 23 is a signal detection circuit (A).

Next, the operation will be described.

The transmission seed signal generated by the reference signal generation circuit (A) 9 and the first
The local oscillation frequencies are mixed by the transmitter 8 and become a transmission signal, which is distributed to the phase shifter group 2 arranged in the vertical plane by the hybrid 4 and the distribution circuit 3 via the transmission / reception switch 10, and a predetermined signal. The antenna element of the array 1 is given a phase amount and radiated into space. The phase setting amount of the phase shifter group 2 corresponds to each phase shifter when the beam scanning angle (or beam number) control signal and timing from the reference signal generation circuit (A) 9 are sent to the beam control circuit 7. Is calculated and given via the phase shifter drive circuit 6.

In this way, the transmission signal radiated in the predetermined direction is partially reflected by the target, and the array 1, the phase shifter group 2,
Low-noise amplification is performed in the high-frequency amplifier circuit 11 via the distribution circuit 3, the hybrid 4, and the duplexer switch 10, and is mixed with the first local oscillation frequency from the reference signal generation circuit 9 in the first mixing circuit 12 to produce the first intermediate signal. After being converted into a frequency signal, the second mixing circuit 13 also mixes with the second local oscillation frequency from the reference signal generating circuit (A) 9 to convert into a second intermediate frequency signal, which is amplified by the intermediate frequency amplifier circuit 14. It is then input to the signal detection circuit (A) 23. This signal detection circuit (A) 2
Reference numeral 3 designates a moving target detection circuit generally called MTI (Moving Target Indicator), a target detection circuit for discriminating a target from unnecessary reflected waves by various detection standards, and intermediate frequency amplification circuits 14a, 14b, 14c. Of the pulse detection circuit based on the outputs of Σ, ΔAZ, and ΔEL, respectively. The output of the signal detection circuit (A) 23 is tracked and calculated by the information processing circuit 17, and displayed on the display circuit 18. It

FIG. 2 shows the beam scanning procedure in the vertical plane, and the detection of the disturbing signal direction is performed in parallel with the target detection performed by this beam in the manner shown in FIGS. 3 to 6.

FIG. 3 shows the transmitted wave within one elevation scanning time, and the interfering signal is observed in the distant area where there is no unnecessary reflection in the short distance within the receiving area corresponding to each beam. Are limited to the channels used for target detection shown in FIG. Relates resulting interference signal beam scanning shown in Fig. 5 in this condition, FIG. 7 of the interference direction detecting circuit (A) 16 in the interference signal direction from the maximum value envelope as shown in FIG. 6 (theta _c ).

[Problems to be solved by the invention]

The conventional radar apparatus has the following problems because the interference signal direction detection is performed by sharing the frequency and timing with the target detection.

(1) The direction of the interfering signal in the radar band other than the frequency used for target detection cannot be detected.

(2) Interfering signal direction detection is limited to azimuth measurement, and elevation angle measurement is not performed.

The present invention has been made to solve the above problems, and an object of the present invention is to obtain a radar apparatus capable of detecting the direction of an interfering signal for all frequencies within the radar band, and for both azimuth and elevation. I am trying.

[Means for solving problems]

The radar device according to the present invention includes (1) a sub-antenna having a fan beam that is wide in a vertical plane and narrow in a horizontal plane, and a disturbance that analyzes the approximate azimuth and frequency of the disturbance signal based on the interference signal output from the antenna. Wave analysis circuit, (2) Only when electronically scanning the interfering signal direction, pulse repetition period with additional time for observing the interfering signal outside the target detection time, and tuning the receiving frequency to the interfering signal only within this time. A reference signal generation circuit having a function of controlling the local oscillation frequency is provided, and (3) an interference direction detection circuit for determining the beam number in the interference signal direction by comparing each beam output during electronic scanning in the interference signal direction. .

[Action]

In the present invention, the frequency and azimuth of the interference signal from the sub-antenna having the fan beam are detected, and the interference frequency is tuned at the timing including the interference wave observation time only when electronically scanning the interference direction to observe the interference wave. By identifying the beam that generated the maximum received signal from the results, it is possible to observe the interfering signal that differs from the target detection frequency.
Highly accurate elevation angle measurement is possible.

〔Example〕

 An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows a phase scanning array radar according to an embodiment of the present invention, which differs from FIG. 7 in the following points.

(1) Since it takes an analysis time to monitor the frequency and azimuth information of the interference signal over the entire radar band, the sub-antenna 21 having a fan beam that is wide in the vertical plane and narrow in the horizontal plane receives it. The interference wave analysis circuit 22 analyzes the frequency and direction by utilizing the fact that the processing time is longer than in narrow beam electronic scanning.

(2) The reference signal generation circuit (B) 19 sets the transmission pulse repetition period to the time required for normal reception of the target signal plus the interfering signal observation time, and for tuning the time to the interfering signal frequency. The function to generate the local oscillation frequency of is added.

(3) The jamming direction detection circuit (B) 20 determines the beam which shows the maximum value of the jamming signal output of each beam in the vertical plane. Further, the signal detection circuit (B) 24 precisely calculates the disturbing signal direction from the disturbing wave output signals (Σ, ΔAZ, ΔEL) during the disturbing wave observation time.

Next, the operation of the above three points, which is a feature of the present invention, will be described in detail.

(1) Interfering signal frequency and azimuth analysis Since processing takes time to monitor the entire radar band, the same azimuth direction can be mechanically scanned by the fan beam as shown in Fig.8. The time for observing the interfering signal becomes longer. Within this time, the interference signal analysis circuit 22 sweeps the frequency to detect the interference signal frequency as shown in FIG. The jamming signal direction can be known from the direction information from the antenna drive circuit (AZ) 5 when the jamming signal can be detected.

(2) Interfering signal precise scanning in the interfering signal direction In the reference signal generating circuit (B) 19, based on the interfering signal frequency and direction information from the interfering wave analysis circuit 22, when the antenna is directed to that direction, The transmission pulse repetition period shown in FIG. 3 is changed to that shown in FIG. 11, and the reception channel is tuned to the disturbed channel shown in FIG. 10 only within this disturbing wave observation time.

(3) Precise measurement of interference signal In the interference direction detection circuit (B) 20, FIG.
The beam number facing the interfering signal is determined as shown in FIG. On the other hand, in the signal detection circuit (B) 24, the interfering wave output signal ((Σ, ΔAZ, ΔE
From L), the interference signal direction is subjected to a monopulse precision calculation in the manner shown in FIG. 14, and after being compared with the interference facing beam number from the interference direction detection circuit (B) 20, it is output to the information processing circuit 17.

The above radar makes it possible to observe an interfering signal in a band different from the target detection frequency, and the direction detection is not limited to the measurement in the azimuth (AZ) direction, and the elevation angle (E
The monopulse angle measurement can also be performed on L).

In the above embodiments, the phase scanning array radar device has been described as an example.
It is obvious that the present invention can be applied to all other electronic scanning array radars such as phase / frequency compound scanning array radar.

〔The invention's effect〕

As described above, according to the radar device of the present invention, the sub-antenna having the fan beam in the monopulse type electronic scanning array radar, the interference signal frequency of the radar whole band by the interference wave analysis circuit, the direction detection function, Using this result, when the main beam scans the disturbing direction, the timing that adds the disturbing wave observation time is generated and the tuning reception function that tunes to the disturbing frequency within that observation time and the disturbing signal output level comparison for each beam Since the configuration is added with the function of precisely measuring the direction, there is an effect that a broadband interference direction detection capability can be obtained for both the azimuth angle and the elevation angle (AZ, EL).

[Brief description of drawings]

FIG. 1 is a functional system diagram showing a configuration of an electronic scanning array radar according to an embodiment of the present invention, FIG. 2 is a diagram for explaining general beam scanning, and FIG. 3 is a conventional transmission timing (1 (For elevation scanning time), FIG. 4 is a diagram for explaining the relationship between the radar band and the frequency channel used, and FIG. 5 is a diagram for explaining the coverage in the azimuth / elevation plane during beam scanning. FIG. 6 is a conceptual diagram relating to a method of calculating an interference signal azimuth by a conventional electronic scanning array radar, FIG. 7 is a functional system diagram showing the configuration of a conventional electronic scanning array radar, and FIG. FIG. 9 is a diagram for explaining the beam shape and azimuth scanning of the sub-antenna according to the present invention, and FIG. 9 is a schematic view showing an analysis method by frequency sweeping for determining the frequency with respect to an interference signal input from the sub-antenna according to the present invention. FIG. 10 is a conceptual diagram showing a control function of a reference signal generating circuit for tuning and receiving only an interfering wave observation time according to the present invention, FIG. 11 is a transmission timing diagram generated by the reference signal generating circuit according to the present invention, and FIG. And the first
FIG. 3 is a conceptual diagram showing the way of determining the disturbing signal direction in the disturbing direction detecting circuit according to the present invention, and FIG. 14 is a conceptual diagram showing the monopulse angle measuring process of the disturbing direction in the signal detecting circuit according to the present invention. 1 is an array, 2 is a phase shifter group, 5 is an antenna drive circuit (A
Z), 19 is a reference signal generation circuit, 20 is an interference direction detection circuit, 21 is a sub antenna, 22 is an interference wave analysis circuit, and 24 is a signal detection circuit. The same reference numerals in the drawings indicate the same or corresponding parts.

Claims (1)

[Claims] 1. A one-dimensional or two-dimensional monopulse type electronic scanning array radar device for directing a beam in an arbitrary direction of one or both of a horizontal plane and a vertical plane, wherein a fan narrow in the horizontal plane and wide in the vertical plane is used. Corresponding to a sub-antenna having a beam characteristic, an interfering wave analysis circuit for detecting the frequency and a general azimuth of an interfering signal entering from the sub-antenna, and a time for the main beam to scan the interfering signal direction detected by the interfering wave analyzing circuit. Then, an interfering wave observation time is provided outside the target detection time, and a reference signal generating circuit that tunes the reception frequency to the interfering signal frequency detected by the interfering wave analysis circuit only within that time, and the observation within the interfering wave observation time A radar device comprising: a jamming direction detection circuit that identifies a beam that has generated a maximum reception signal based on a result.