JPS5999372A - Radar equipment - Google Patents

Abstract

PURPOSE:To eliminate restriction on the selection of frequency used with a shorter required time of a beam scanning by arranging a transmission module so as to form a plurality of receiving beams corresponding to a plurality of transmitting beams simultaneously formed in a time sharing manner while a receiver corresponding to the receiving beams outputted from a transmitting/receiving module. CONSTITUTION:A phase setting phi1-1 determined by a frequency f1 and a directing elevation angle of a beam #1-1 is provided to a transmission phase shifter of a transmitting/receiving module to transmit the beam #1-1 and then, a phase setting phi1-2 determined by a frequency f2 and a directing elevation angle of a beam #1-2 and a phase setting phi1-3 determined by a frequency f3 and a directing elevation angle of a beam #1-3 are provided successively to the transmission phase shifter to transmit the beams #1-2 and #1-3. On the other hand, at the reception, phase settings phi1-1, phi1-2 and phi1-3 of the beams #1-1, #1-2 and #1-3 are provided to three individual receiving phase shifters of the transmitting and receiving module simultaneously to form three reception games simultaneously. Likewise, the transmission and reception are repeated.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a means for forming multiple receive beams in a phased scanned array radar system to reduce the time required for pencil beam scanning.

An example of a conventional phased scanning array radar device is
As shown in Figure 1, there was a one-dimensional phase scanning array radar system that used phase scanning only in the elevation direction and mechanical rotation in the azimuth direction.

Here, for convenience of explanation, the explanation will proceed assuming that each of the beams #1 to #m is transmitted in units of 1 pulse.

As shown in Fig. 1, the constant elevation distortion method used in the conventional device is to sequentially change the directional elevation angles of m beams #1 to m, and perform transmission and reception (repeatedly to obtain the total elevation angle coverage K). The beam scanning at this time is generally controlled by a single transmitting/receiving phase shifter corresponding to the element antennas of the array antenna. An example of the relationship between waveform and time is shown in FIG.

In the figure, the transmission pulse interval T1 to -1' m changes from T1 to Tm as the slant range determined from the coverage area H- decreases, corresponding to beams #l to #m. The transmission pulse width nrt~τm also decreases from T1 to τm as the oblique distance decreases.
It gradually becomes narrower. At this time, the time required to scan the required elevation angle coverage area, that is, one elevation angle scanning period 'r,
is the integrated value Σ'l' i of the transmission pulse intervals T1 to Tm.

1 = 1 From the above explanation, - in the conventional method of scanning the entire elevation angle range K with one pencil beam, one elevation angle scanning period T.

The disadvantage was that it had to be long.

As an improvement on the conventional method,
There was a frequency set meal. This is to control the beam pointing elevation angle by the phase difference generated by changing the frequency of the transmitted signal propagating through a transmission line of a certain length. By changing the frequency of the beam, it is possible to form multiple beams. However, this method has the disadvantage that the frequencies must be maintained at one-foot intervals for elevation angles that are at constant intervals, and the degree of freedom in selecting the frequency to be used by the radar is small.

The present invention has been made to eliminate the drawbacks of the prior art as described above, and it forms multiple transmit beams in a time-divisional manner, and simultaneously forms multiple receive beams corresponding to the multiple transmit beams. By configuring the transmitting/receiving module so as to be able to transmit and receive, and providing receivers corresponding to the plurality of receiving beams output from the transmitting/receiving 4a module, the time required for beam set meals can be shortened, and there are no restrictions on the selection of frequencies to be used. The purpose is to provide a radar device that does not require a beam traverse.

Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

In this example, for convenience of explanation, as shown in FIG.
An explanation will be given of a set meal system that is a -dimensional phased scanning array radar device and uses three beams as a group to scan the required elevation angle. FIG. 4 shows the relationship between the transmission waveform and time of this radar device. Again, for convenience of explanation 1, the explanation will proceed assuming that each of the beam groups #1 to #n is transmitted in units of l pulses.

FIG. 5 shows the configuration of the main parts of a radar device according to an embodiment of the present invention, in which (1) is an array antenna, and the array antenna (1) is a transmitting/receiving module (
2) an element antenna excited by (3) a transmitting distributor (4) that sends a transmitting signal f0 to the fist transmitting/receiving module (2);
, each receiving combiner (5a) to (5C) for combining the three beams of received signals from each transmitting/receiving module (2).
Each received signal from the -1 ray antenna (1) consisting of receivers (101), (10b), (1
The local oscillation signals from the stabilizing local oscillators [8a] to (8C) are sent to the mixers (7a) to (7), where they are amplified by the low noise amplifiers (6a) to (6C), and then mixed into intermediate frequency signals by the mixers (7a) to (7). After conversion, band pass fill (9a)~
(9C), each frequency is selected to become a received signal of the desired intermediate frequency. Note that the element antenna (3) here is an array antenna (1) that is a -dimensional phase fixed type. If all the element antennas in the azimuthal direction are 1
It is considered as one antenna.

FIG. 6 shows the configuration of the transmitting/receiving module (2) constituting the array antenna (1+), in which the transmitting signal from the transmitting divider (43) is sent to the transmitting phase shifter @ to adjust the required inter-element phase. A phase difference is given, and this transmission 1=signal is transmitted to the power amplifier −,
It passes through the circulator (2) and is radiated from the system antenna (3). Further, the received signal received by the element antenna (3) is sent to the circulator (2).

'After passing through the J transmitter (c), being amplified by the low noise amplifier (to), and being distributed by the divider (2), it passes through each of the receiving phase shifters (21a) to (21C) to the receiving combiner. (5a
) to (5C).

Next, the three-beam elevation angle scanning method in the radar device of this embodiment is as follows.

Generally, in an array antenna (1) with a -dimensional phase constant distortion, the relationship between lI/iAd between the element antennas (3J) and the phase difference φ between the elements is expressed by the following equation.

2πd cosθ=φχ Here, λ: Wavelength of transmission frequency θ: Beam finger co-elevation angle In FIGS. 3 and 4, beam group #l is formed as follows. First, the phase setting φl-1 determined by the frequency 11 and the directional elevation angle of the beam $1-1 is applied to the transmitting phase shifter (2) of the transmitter/receiver module (2), and the beam #l
-1, then frequency [2 and beam #1
The phase setting φ determined by the directional elevation angle of t-beam #1-2 is roughly determined by the frequency f3 and the directional elevation angle of t-beam #1-3. 2) and transmits beam #-3 1-2, 4tl-3. In this way,
Three beams during transmission are formed in a time-division manner.

- 10,000, at the time of reception, 3 of the transmitting/receiving module (2)
receiving phase shifters (21a), (21b), (21
C) Beams #l-1, +1-2, respectively. +1-3
The phase settings φ□-1, φl-2, and φ1-3 are applied simultaneously, thereby forming three reception games at the same time. Similarly, by sequentially repeating the above transmission and reception for #2 group, #3 group, . . . #n group, it is possible to scan the required elevation angle coverage area.

If the distance coverage of #1 to #3 in FIG. 1 is the same as the distance coverage of beam group #1 in FIG. 3, then the integrated transmission pulse interval of beams #1 to #3 in FIG. Value (T
□T2+"3) and the transmission pulse interval ゛r1' of beam group #l in Fig. 4, it is found that although the transmission pulse width τ (is three times as large as
1 is the 21st. ! ! The integrated value of the transmission pulse interval at J5 (
−r
is 1 elevation angle travel 1=1 in FIG. 2. Also, the frequency 11·f2. f, no 4
・For 1 mutual advantage, since the phase difference between the element antennas can be arbitrarily determined from the directivity elevation angle and the transmission frequency, the above frequency f□Ifglf3 can be selected freely. , receiver band pass filter (
For example, if the pass frequency bands of 9a) to (9C) are set to divide the frequency band used by a radar device into three, there will be some restrictions on the selection of the three frequencies, but this band pass filter (9a) ] to (9C) are narrow band electronic tuning filters, and if the tracking interval is opened according to the frequency used, this constraint can also be solved t184.

In the above explanation, we have talked about the scanning method in which three beams are set as a group, but in order to increase the number of beams, the number of distributions related to the distributor in the transmitting/receiving 1M module (2), the receiving phase shifter D,
It would be a good idea to increase the number of receiver channels after the receiving synthesizer (51, Kuzuyo and low-axis sound amplifier (6)) according to the number of beams. Top, transmitting distributor (4) and receiving 1H combiner (5)
, and the transmission phase shifter (2) and the reception phase shifter (tall) have been described separately, but they are essentially the same.

2'j In the above embodiment, a radar device using a -dimensional phase scanning method has been described, but the same effect as in the above embodiment can be obtained also in the case of a two-dimensional phase scanning method. Also 1
The present invention can also be applied to a beam scanning method that is a combination of a frequency scanning method and a phase scanning method.

Further, the beam scanning direction and order in FIG. 3 are merely examples, and "C" can also be applied to a different scanning direction and order.

As described above, according to the present invention, the transmitting/receiving module is configured so as to be able to simultaneously form a plurality of receiving beams, and a receiver is provided corresponding to the plurality of receiving beams emitted from the transmitting/receiving module. Therefore, the time required for beam scanning can be shortened, and a radar device that does not require restrictions on the operating frequency can be obtained. 2
The diagram is! 41 is a diagram showing an example of a transmission waveform in the scanning method; FIG. 3 is a diagram showing an elevation scanning method in a one-dimensional phase scanning array radar device according to an embodiment of the present invention;
The figure shows an example of the transmission waveform in the scanning method shown in Figure 3.
The fifth figure is a block configuration diagram of the main part of the one-dimensional phase scanning f7° ray radar device d according to an embodiment of the present invention, and the sixth figure is a diagram showing an example of the configuration of the transmitting/receiving module of the radar device. .

(1)...Array antenna, (2)...Transmission/reception module, (3)...Element antenna, (4)...Transmission distributor, (5a) (5b) (5C)... Reception synthesizer, (10a) (10b) (IOC)...receiver.

f: '16 The same reference numerals in the drawings indicate the same or corresponding parts.

Agent Nobu Kuzuno - Figure 1 Figure 2

Claims (1)

[Claims] +11 In a phased scanning array radar device that electronically scans a pencil beam by equipping each of the r element antennas with a phase shifter, the input transmission signal is transferred to the r element antennas. One transmitting distributor for distributing the signals to each of the transmitting distributors, and one transmitting beam is formed in a time-divisional manner by receiving the transmitting signal from each transmitting distributor, and the above-mentioned is transmitted from the signal received by the element antenna. r transmitting/receiving modules that simultaneously form one receiving beam for one transmitting beam; and r transmitting/receiving modules provided corresponding to one receiving beam formed by one of the r transmitting/receiving 1g modules. one reception combiner that combines one reception beam from each of the transmission and reception modules, and one reception combiner that receives the output from each of the reception combiners. A unique device characterized by: