JPS58132676A - Tracking radar for searching semispherical space - Google Patents

Abstract

PURPOSE:To shorten a time required for searching and to improve a distance performance, by covering the radar-covered area of the whole upper semispherical space with antennas for the direction of zenith and for a space area at low and medium elevation vertical angles. CONSTITUTION:A zenith area antenna 3 performs beam scanning within a conical space at an open angle of 40 deg. in the direction of zenith, based on a phase control signal 6, while, in horizontal-area antennas 4 and 5 each emitting four beams, the beams totaling eight are made to scan the entire circumference at an elevation vertical angle of 0 deg.-50 deg. based on a phase control signal 7. The eight beams are mae to scan by a mechanical turning in the direction of an azimuth, while they are made to conduct phase scanning independently in the direction of an elevation vertical angle. The antenna 3 is supplied with an excitation output from an exciter 8, and a monopulse receiver 9 processes a reception signal 10 based on a local signal and a COHO signal 11. On the other hand, in the transmission system of each of the horizontal-area antennas, an output of a synthesizer 12 is supplied to an exciter and distributor 13, and a transmission power is supplied via phase shifters 14 and 15, power amplifiers 16 and 17, and a hybrid 18.

Description

[Detailed Description of the Invention] The present invention relates to a radar device that searches and tracks multiple targets throughout the upper hemisphere space around a radar installation point.
The present invention relates to a practical system characterized in that beam scanning is performed using a multi-beam as an antenna at fF by a combination of electronic scanning and mechanical scanning.

As shown in FIG. 1, conventional radar devices of this type have an antenna configuration in which a mechanically rotating planar electronic scanning antenna is provided on only one side and a single pencil beam scans a hemispherical space.

In FIG. 1, (1) is an electronic scanning antenna in which a large number of phase shifters etc. are arranged in a plane, and the beam scanning angle range is practically only about ±50 angles.

The antenna gain inevitably decreases in proportion to the beam scanning angle, it takes a long time to scan the entire circumference of the beam because it is mechanically scanned with a single beam, and the beam irradiation to the target is short. There are drawbacks such as a short detection distance due to a small number of pulse hits, and in order to compensate for these drawbacks, a high-power transmitter must be used.

This hindered the practical application of radar that covers hemispheric space.

In order to eliminate these drawbacks, this invention uses two types of antennas to share the hemispherical radar coverage area, and a strategic low-to-medium elevation antenna system equipped with multiple slot array antennas that simultaneously radiate multiple beams from an aperture surface. By using the antenna configuration and multi-beam scanning that combines electronic scanning and mechanical scanning, it is possible to provide a practical radar system that can cover the entire hemispheric space while reducing search time and improving distance performance. It is something to do.

Below, as an embodiment of the present invention, an antenna is shown in FIG.
The figure shows the radar transceiver system.

In Fig. 2, (2) is the radome, (3) is the first electronic scanning antenna attached to the fixed part of the antenna mount facing the zenith, and f4H5) is the waveguide antenna that is placed back to back around the mechanical rotation axis. This is a second antenna that has a double-opening plane of a tube slot array and is configured to be able to electronically scan multiple beams independently in the elevation angle direction. In the specific example below, the first antenna (3) emits one monopulse beam capable of biaxial electron beam scanning, and the second antenna (4)
In (5), the antenna and radar transmission/reception system will be explained assuming that four monopulse beams with fixed azimuth angles are phase-scanned independently in the elevation angle direction for each plane.

Note that hereinafter, the first antenna will be referred to as the sky antenna, and the second antenna will be referred to as the horizontal antenna.

In Figure 3, the Zenith Mound antenna (3) scans the beam in a conical space with an opening angle of 40 degrees in the zenith direction using the phase control signal (6) K, and the horizontal area antennas +41 and +51 have 4 each, totaling 8 The book beam is scanned around the entire circumference from an elevation angle of 00 to 50 degrees based on the phase control signal (7). The eight beams are scanned by mechanical rotation in the azimuth direction, and independently phase scanned in the elevation direction.

The division of the radar range may be appropriately overlapped.

Excitation output is supplied to the zenith antenna (2) from the exciter (8), and the monopulse receiver (9) receives the monopulse 3
Local signal and C0H after receiving channel reception signal
Reception processing is performed using the O signal (11).

On the other hand, in the transmission system of 9 mechanically rotating horizontal area antennas, the output of 1 frequency synthesizer q is supplied to exciter and distributor 0, and variable phase shifter α4. Power amplifier-1 and power amplifier-2a are connected through fixed phase shifter Q5, respectively.
The power is amplified.

Transmission power is supplied to each horizontal area antenna (41 (51) in the hybrid Q8.

At this time, two people (19m) went to Hybrid J →.

The phase difference of (19b) is controlled by the variable phase shifter I before amplification, and the summed output is obtained from different output terminals (20m) (20b), and is generated by one frequency synthesizer Q.
Add f1 to f4 to the transmission pulse consisting of eight sub-pulses of f1 to f8 shown in a), and output the output shown in FIG. 4(b) as (20a) to the horizontal antenna (5).

Also, add f5 to f8 and get the output shown in Figure 4 B→ (20
b) is supplied to the horizontal antenna (4).

The amplitude of IH in Figure 4 (A) is drawn larger than J in Figure 4 (A), indicating that the power is doubled due to addition. After the above power synthesis and switching are performed, The transmitted wave is guided to the antenna via a transmitter/receiver switch (21) (22X-). (23) is a system programmer.

(24) is a beam scanning section.

Next, in the reception system of horizontal area antenna +41 (5).

The received signals from the antenna +41 (5) are added together in the adder (26) as a monopulse summation channel, amplified by the RF amplifier, and mixed with the local signal (29) by the mixer (28) to convert the IP flaw signal into a broadband amplifier (60). After being amplified by the filter group (61), the signal is separated into eight signals corresponding to the beams, and the signals are converted into eight signals by a single phase plate waveform generator (52).

The phase is detected by the signal (36), and the A7'b converter (
34), it is converted into a digital value and used for subsequent signal processing.

For the azimuth angle difference channel, a transmission/reception switch (35), an adder (36), and a receiver (37), and for the elevation angle difference channel, a transmission/reception switch (38), an adder (39), and a receiver (40). The same reception processing as for channels is performed.

FIG. 5 shows multi-beam scanning in hemispherical space.

(41) shows the zenith beam, and the others show eight uniaxial electronic scanning beams only in the elevation angle direction from the horizontal area antenna.

Hereinafter, specific examples of horizontal area antennas will be shown. Fig. 6 shows an example in which four two-channel monopulse beams having only the sum and elevation angle difference are emitted per surface, and Fig. 7 shows an example in which four two-channel monopulse beams are emitted per surface.
Another embodiment will be shown in which three channel monolithic beams of sum, elevation angle difference, and azimuth angle difference are emitted in the same way.

In Fig. 6, (50) is the longitudinal coalet foot, and (51) is the sum and difference of the upper and lower halves of the corporet feed to form a monopulse sum channel and an elevation angle difference channel. Sum-difference circuit, (52
) is a duplexer that separates the four sub-pulse waves f1 to f4 shown in FIG. 4(b) according to frequency.

(53) is a four-beam phase shifter that scans the elevation angle of four beams independently, and (54) is a Patra matrix power supply circuit with four terminals in the row direction shown in Fig. 8, with different fixed Four beams are formed in four azimuth directions corresponding to transmission sub-pulses of frequencies f1 to f4.

(55) is a waveguide with slots in the row direction.

The number of slots arranged in the vertical direction corresponds to the number of output terminals of the coalette power supply (50), and constitutes the opening surface of the slot array.

(56) is the transmitted wave shown in Figure 4 (b), (5Q (
58), (59).

(6[1), (61) for the ti monopulse sum channel.

Transmission/reception switch, RF amplifier mixer, wideband IF amplifier, filter group, (62), (63), (64),
(65) and (66) are a transmitting/receiving switch, an RF amplifier, a mixer, a wideband IF amplifier, and a filter group regarding the elevation angle difference channel.

In FIG. 7, (70) is a longitudinal coholet feed, (71) a sum-difference circuit for configuring the i monopulse sum channel and elevation angle difference channel, (
72) is a branching filter, (73) a phase shifter, (74)
is a Patra-matrix feeder circuit with eight terminals as shown in Fig. 9, and (75) is a combination of the eight beams shown in Fig. 9 to form a monopulse beam having the sum and azimuth difference of the four beams shown in Fig. 10. circuit, (76) is a waveguide with slots in the row direction, (77) is a multiplexer that combines four waves of azimuth difference signals related to four beams, (78) is a coholet that combines the azimuth difference signals in the vertical direction The feed (79) is a sum-difference circuit whose phase terminal becomes a four-wave azimuth difference channel output.

(80) is the transmission wave, (81) is the transmitter/receiver switch, (8
2) is the RF amplifier (83), (84) is the broadband IF amplifier, and (a5) is the filter group, and the subscripts a, b, and c indicate the sum channel, elevation difference channel, and azimuth difference channel. show.

FIG. 8 shows a Patra matrix circuit with 4 terminals,
(90) is 3dB hybrid, (91) is -
Input port "1" with 5 phase shifters ~ 8 depending on leap
Indicates that a beam is formed in the direction.

FIG. 9 shows a Patra matrix circuit with 8 terminals,
(92) is 3dB hybrid, (93) is 3dB hybrid
This shows that the beam is formed in eight different directions depending on the input port "1" and the input port "1".

Figure 10 shows the monopulse 4-beam reception pattern by the combining circuit (75) of Figure 7 (100) in Figure 1.

(101) is the sum and difference pattern of beams r2j r6J in Fig. 9, (102) and (103) are beam r4J
18J sum and difference pattern, (104), (10
5) is the pattern of the sum and difference of beams “1” and “5”, (
106) and (107) show the sum and difference patterns of beams r3J r7J.

Since the present invention has the above configuration, it has various advantages as shown below compared to the conventional electronic scanning antenna which scans a hemispherical space with one beam from one surface.

First, because it is a multi-beam antenna, the beam scanning time for complete hemispheric space destruction is shortened while maintaining a sufficient number of pulse hits, making it possible to improve radar distance performance, high reception data rate, etc., and improve overall radar performance. It can be improved and put into practical use. Second, the elevation angle of two of the four beams on one surface is fixed to the horizontal plane, and the other two beams are used for covert search of elevation and elevation angles. Thirdly, for the first detection target in the horizontal area, by controlling the transmission sub-pulse frequency to the horizontal area antenna, the beam backscan during zero mechanical arm rotation and the adjacency of multiple beams can be configured. By widening the beam width, it is possible to temporarily increase the number of pulse hits during the target acquisition process and improve the acquisition probability.

FIGS. 11 and 12 show an example of the transmission waveform and beam scanning at this time.

Figure 11 (a) is the waveform during normal search, Figure 11 (b)
is a transmission waveform in which the four waves of f1 to f4 are changed to adjacent 5v waves of f and f6.

In Fig. 12, (110) is the initial detection azimuth direction.

(111) to (115) 5 adjacent beams corresponding to the subpulses of ke fl and ~f0, (116) to (j19) beams corresponding to the subpulses of f5 to f8, (12
0) is the antenna rotation direction.

At this time, since the frequencies f and f6 are close to each other, the 5-beam signal is not separated by the receiving filter but passes through one specific filter.

[Brief explanation of drawings]

FIG. 1 is a diagram showing a conventional antenna configuration, FIG. 2 is a diagram showing an example of an antenna configuration according to the present invention, FIG. 3 is a diagram explaining a radar system according to the present invention, and FIG. 4 is a diagram showing a transmission waveform. Fig. 5 is a diagram showing beam scanning in hemispherical space, Fig. 6 is a diagram showing one embodiment of the horizontal area antenna, Fig. 7 is a diagram showing another embodiment of the horizontal area antenna, and Fig. 8 is a diagram showing 4 terminals. the patroller
Figure 9 is a diagram showing a matrix, Figure 9 is a diagram showing an 8-terminal Patler matrix, Figure 10 is a diagram showing a composite pattern,
FIG. 1 is a diagram showing a transmission waveform during acquisition, and FIG. 12 is a diagram showing beam scanning during acquisition. In the figure, (1) is an electronic scanning antenna, and (2) is a radome. (3) is the zenith antenna, f41 (5) is the horizontal antenna, (6) and (7) are the phase control signals, (8) is the exciter, (9) is the monopulse receiver, OIU monopulse 3 channel received signal, Ql) is a local signal and C0HO signal 1 ring is a frequency synthesizer, 113 is an exciter and distributor, a4Fi variable phase i, tts is a fixed phase shifter, α
G is power amplifier-1, (Iη is power amplifier-2, QB is) hybrid, (I9 is input, wire is output, CI'1
1 (c) is the transmitter/receiver switch, (to) is the system programmer,
Q4 (c) is the beam scanning section, (c) is the adder, @ is R
F amplifier, ■ mixer, (to) is local signal, C! 6
is a wideband IF amplifier, (31) is a filter group,
(32) is a phase detector. (55) is the C0HO signal, (54) is the A/D converter, (35) is the transmitter/receiver switch, (36) is the adder,
(37) is the receiver. (38) is a transmitter/receiver switch, (39) is an adder, (40
) is the reception 1 (41) is the zenith beam, (50) is the coho left feed, (51) is the sum-difference circuit, (52)
is a duplexer, (53) is a phase shifter, (54) is a Patra-matrix feeder circuit (55) is a slotted waveguide,
(56) is the transmission wave, (57) is the transmitter/receiver switch,
(58) is an RF amplifier, (59) is a mixer, (6
0) is a wideband IF amplifier, (61) is a filter group,
(62) is a transmitter/receiver switch, and (63) is an RF amplifier. (64) is a mixer, (65) is a wideband IF amplifier,
(66) is a filter group, (70) is a coalet feed. (71) is a sum-difference circuit, (72) is a duplexer, (73)
is a phase shifter. (7ri is a Patra matrix feeder circuit, (75) is a synthesis circuit, (76) is a slotted waveguide, (77
) is a multiplexer, (78) is a coalet feed,
(79) ii sum-difference circuit, (so) is the transmitted wave, (8
The transmitter/receiver switch, (82) RF amplifier, (83
) is a mixer, (84) is a wideband F amplifier, (8
5) is a filter group, (90) is a 3 dB phase shifter, (91) is a -5 phase shifter, (92) is a 3 dB
/・Ibrid, (95) is -i phase shifter, (94
) is -V phase shifter, (95)ld-”-7 phase shifter,
(100) ha r2J + r6J. (jol)Fir2J-r6J, (102) is l'-4J + lfJ, (103) is r
4j −r8j , (104) is 11j +
[5j, (105) is "1" - [sj
, (106) is r3j +r7J , (
107) is r3J −r7J. (110) is the initial detection azimuth direction, (111)・〜(1
15) is each beam of f, , ~f8, (116) ~(
119) are each beam of f5 to f8. (120) is the antenna rotation direction. In the drawings, the same or corresponding parts are designated by the same reference numerals. Agent Shin Kuzuno - 1n Ne 2 Shame 4 B '475 Aki 1 θ Juku 7 Hane rrgA Mine 10 Hatake 'l Hatake Juku 11 Shame

Claims (6)

[Claims] (1) In a radar device that emits radio waves toward a target and uses the reflected waves to search for and track the target, the radar coverage area is a cone of 9 clays in the direction of the zenith, and it is installed facing the zenith. It is equipped with a first antenna and a second antenna whose radar coverage area is 9 ranges of low and medium elevation angles around the entire circumference other than the conical airspace, and the first antenna. A hemispherical space search radar, characterized in that the second antenna covers the radar coverage area of the entire upper hemisphere space. (2) In a radar device whose radar coverage area is the entire upper hemisphere space centered on the radar installation point, a first antenna facing the zenith electronically scans a conical sky area in the zenith direction with a pencil beam, and mechanically rotates an electronic scanning antenna that has a plurality of pencil beams emitted in different directions, and each beam can scan the electron beam independently only in the elevation and elevation directions. A hemispherical spatial search and tracking radar characterized by comprising a second antenna for beam scanning. (3) Configure multiple independent systems of radar transmitting/receiving devices, radar signal processing devices, etc. related to the first antenna and second antenna, and depending on the application and purpose, the radar coverage area can be completely destroyed in the hemisphere, only in the zenith area, or in the horizontal area. The hemispherical spatial search and tracking radar according to claim (2), characterized in that the hemispherical spatial search and tracking radar can be switched only to (4) The aperture is a planar slot antenna in which a large number of waveguides with slots in horizontal rows are arranged vertically. As a feeding system, the vertical coholet feed and sum difference circuit that constitutes the sum channel and elevation difference channel of multiple beams are connected to each output end of the coholet feed, enabling independent beam scanning in the elevation angle direction of multiple beams. A branching filter, a plurality of phase shifters, a power supply circuit network connected to the outputs of these phase shifters, and an upstream power supply circuit of a Patra matrix for configuring a plurality of beams with fixed azimuthal directions corresponding to the transmission frequency, and the above-mentioned Patra matrix A second electronic scanning antenna is provided with a circuit that supplies multiple outputs from the slotted waveguide to the slotted waveguide.
A hemispherical spatial search and tracking radar according to claim (2) used as an antenna for. (5) Claims characterized in that the number of terminals of the Patra matrix and the number of apertures of the second electronic scanning antenna are selected so as to equally divide the entire circumference into a plurality of beams fixed in the azimuthal direction. The hemispherical spatial search and tracking radar described in paragraph (2). (6) The opening plane is a planar slot array anti-waveguide in which a large number of waveguides with slots in the row direction are arranged vertically, and the vertical first waveguide is used as a feed system to constitute the sum channel and the elevation angle difference channel of multiple beams. a cohollet feed and sum-difference circuit, a multiplexer corresponding to each slotted waveguide constituting the direction angle difference channel of multiple beams, and a second coholet feed and summation circuit that combines the outputs of these multiplexers. A difference circuit, a splitter and a plurality of phase shifters connected to each output end of the first coholet feed to enable independent beam scanning of multiple beams in the elevation direction, and multiple beams fixed in the azimuth direction corresponding to the transmission frequency. In order to configure a Patler matrix with a number of terminals that is 2'' (n is an integer) times the number of required beams, and a sum channel of a plurality of target beams from 211 beams formed by the above Patler matrix, and a combining circuit for obtaining the azimuth difference channel output 1. A circuit for supplying the azimuth difference channel output from the combining circuit to the multiplexer, 2n from the Patra matrix.
a monopulse multi-beam electronic scanning anti-narrow configuration having three channels of sum, elevation angle difference, and azimuth angle difference for each of the plurality of required beams; A hemispherical spatial search and tracking radar according to claim (2), characterized in that this antenna is used as a second antenna.