JPH03220475A - Radar - Google Patents

Abstract

PURPOSE:To enable the formation of a transmission beam to a plurality of targets simultaneously by dividing a conformal array antenna into a plurality of areas to calculate a phase value in the formation of beams corresponding to targets different in direction. CONSTITUTION:First, a conformal array antenna 1 is divided into (n) areas of according to directions of targets 181 - 184. Then, a phase value is calculated for each of the areas corresponding to phase devices 141-14n belonging top the respective areas divided and (n) transmission beams 201-2014 are synthesized simultaneously accordingly. The radio waves thus transmitted are reflected respectively on the targets 181-184 to be received independently as received beams 211-214. Therefore, the control of the phase devices 141-14n is divided into areas to allows the formation of a multibeam for the transmission simply by computation for each area. This enables the utilization of a radiation energy of the antenna 1 to the fullest while characteristic in the formation of the multibeam by the formation of a digital beam is utilized effectively thereby achieving a detection distance significantly.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a radar system using a conformal array antenna and digital beam forming.

[Conventional technology]

FIG. 2 is a diagram showing the structure of a conventional radar device. In FIG. a hemispherical structural base that constitutes a
(51) to (5n) are n elements arranged along the structural base (2), and (4+) to (4n) are connected to the phase shifters of the elements (51) to (5n). The phase shifter control signal line (5) is the phase shifter control signal line (41) to (4).
(71) to (7n) are microwave power dividers connected to the transmission system of the above elements (31) to (3n), (91) to (9n) are the above elements (
31) to (5n) receiving system signal lines connected to the receiving system, (
to) is a digital beam forming circuit connected to the receiving system signal lines (91) to (9n). FIG. 3 is a configuration diagram showing the flow of signals in the antenna section of a conventional radar device.

(51) to (5n) are elements (41) to (4n) are signal lines for controlling a phase shifter, (5) is a phase controller, (61)
) to (6n) are element antennas, (eye 1) to (I In)
is a transmitter/receiver switch.

(+21) ~ (12n) are the above transmission/reception switch (++1) ~
(lln) K-connected transmission systems, (Ih) to (+Sn) are high output amplifiers that constitute the above transmission systems (+2.) to (+2n), (141) to (+40) are the transfer systems that constitute the above transmission systems. Phase box, (c) to (7n) are the above transmission system (+21)
-(+zn) are the transmission system signal lines connected to the above transmission system signal lines (71) - (7n), (8) are the microwave power dividers connected to the above transmission system signal lines (71) - (7n), (+51) - (+sn) are the above transmission/reception switchers ( Receiving system connected to ++, ) to (+ +n), (16
1) - (+6n) are low noise amplifiers that constitute the above reception system (Ih) - (+sn), (+71) - (17n) are analog-digital converters that constitute the Kamiyu reception system (+St) - (15n) , (9*) to (9n) are reception system signal lines connected to the reception systems (+s1) to (15n), and αe is a digital beam forming circuit connected to the reception system signal lines.

Next, the operation will be explained. The microwave signal input from the transmitter to the microwave power divider (8) is.

It is distributed to the output of the n terminal with the desired amplitude and two phases.

The element (5) is connected via the transmission system signal lines (71) to (7n).
1) to (5n) are transmitted to transmission systems (+2t) to (+20).

The microwave ministry name is the transmission system of elements (31) to (3n).

(+21) to (12n) phase shifters (141) to (+an
) - the element antenna (61) attached to the structural base 12) of the conformal array antenna (1) via the high power amplifiers (+51) to (13n) and the transmitter/receiver switchers (lh) to (lln) ) to (6n) are radiated into space.

At this time, in the conventional radar, each element antenna (61) to (6n) is used to radiate radio waves in a desired direction.
) so that the radio waves emitted from
The correction amount φi is set to 2π for the desired direction (θ, φ).

φi=7 (s tnθcosφxi+stnθsi
nφyi+ cosθ・Zi) ・・・・・・
・・・・・・fi+Here, λ=wavelength of radio wave is calculated, and 1 phase controller (5) controls each phase shifter (14, )
~(14n).

The microwave signal radiated into space is reflected by the target, received again by the element antennas (61) to (6n), and transmitted through the transmitter/receiver switchers (Ih) to (I In) to the elements (51) to (5).
n) receiving system (+51) to (15n) K are transmitted.

The microwave signals input to the receiving system (+s1) to (+5n) are as follows.

It is amplified by low noise amplifiers (lh) to (+6n). Microwave signal amplified by low noise amplifier (+61) to (+6n) Analog digital converter (17s) to (17n)
), the signal is converted directly or after frequency conversion into a digital signal containing phase and amplitude information.

The digital signal is transmitted through the receiving system signal lines (91) to (9n) and converted into a digital beam rather than a microwave signal using techniques such as individual Fourier transform, fast Fourier transform, and Winograd Fourier transform in the digital beam forming circuit (to). Beam-combined as signals.

Therefore, the signals from elements (51) to (5n) can be digitally multiplied by correction values and synthesized arbitrarily, making it easy to synthesize patterns such as low side lobe and null beam synthesis. can be synthesized.

[Problem to be solved by the invention]

Since conventional radar equipment is configured as 9 or more,
It is not possible to simultaneously irradiate targets from multiple directions with transmit beams, and it is necessary to switch transmit beams over time, which does not take full advantage of digital beamforming, which allows multiple beams to be combined during reception. Ta.

This firing was done in order to solve the problems mentioned above, and the purpose is to obtain a radar device that can simultaneously form transmission beams to a plurality of targets.

[Means for solving the iJ1 problem] The radar device according to the present invention uses a multi-beam as a transmission beam, efficiently transmits radio waves to a target, and can deal with multiple targets simultaneously. .

[Effect]

In this invention, in order to calculate all the phase shifts to the phase shifters (141) to (14n) necessary to form a multi-beam during transmission, the conformal array antenna (1) is divided into a plurality of nine regions. By calculating the amount of phase shift to form beams corresponding to targets in different directions, multi-beam formation is performed without using special algorithms, and radio waves are efficiently radiated to the target. This is what made it possible.

〔Example〕

An embodiment of the present invention will be explained below.
In (1) is a conformal array antenna,
(181) to (18a) are the targets e C"1') to (+
94) is a conformal array antenna (
11 4 Tsukuda areas, (2(h) to (20a) are areas (+
The transmit beams (2h) to (214) are formed using the transmit beams 91) to (+94), respectively, and the transmit beams (2h) to (214) are independent beams synthesized by the digital beam forming circuit αG using all areas of the conformal array antenna (1). There are four receiving beams.

Next, the operation will be explained. Now consider four targets (181) to (+Sa) in angular directions separated by 90 degrees. First, conformal array antenna (1) is placed in four areas (19
1) to (194). In the phase controller (5), the phase shifters (+4.) to (14n) belonging to the divided regions (181) to (184), respectively, correspond to K, and the @ region (+a1
) ~ (+134), the phase shift amount is calculated using the formula shown in formula (11), and the four transmitting beams (201) are calculated accordingly.
~(204) are synthesized simultaneously. The transmitted radio waves are
The received beams (211) to (21a) are reflected by the targets, respectively.
) are received independently. At this time, the transmission beam (zol
)~(20j) and the receiving beam, their antenna gains are GTX s'rx GRX 5RX GTX: Gain of transmitting antenna GRX: Gain of receiving antenna STX: Area relative to target direction (201)~(
Projected area SRX of each of the transmitting beams (2(h) to (204)) is different from that of the receiving beams (2h) to (21n). Although the gain is smaller, the search range can be searched in four directions simultaneously and quadrupled, so the radio wave irradiation time per target (181) to (+84) is quadrupled, and the number of integrations in signal processing is quadrupled. In this case, it becomes clear from Figure 1. - If the boat fishing is divided into Kn, it will become larger by 1/n.Also, R40e integral number/transmission antenna gain R: Radar detection distance will be significantly increased. improves.

In the above embodiment, a hemispherical structural base (4) is used as the conformal array antenna (1), but the structure is not limited to this and can be applied to a ship.

Even if it is a shape that has a part or multiple parts of a curved surface of the outside of a structure such as an aircraft, missile, land vehicle, satellite, ground radar site, etc., a part of a cylinder with 9 balls, 1 cone, etc., or a combination of these shapes. good.

Further, regarding the conformal array antenna (the number of divisions into 110), the same effect can be expected even if the number of divisions is not limited to 4 and is arbitrarily divided into 2 or more.

Needless to say, the number of targets to be dealt with and the direction of the targets are not limited to this case, and can be arbitrarily determined.

〔Effect of the invention〕

As described above, according to the present invention, by dividing the control of the conformal array antenna (11 phase shifters into 9 regions of n) during transmission, a simple method similar to the conventional method can be performed for each region of n. By simply performing calculations, it becomes possible to form multi-beams during transmission, making it possible to fully utilize the radiation energy of the conformal array antenna (1), as well as effectively utilizing the multi-beam forming characteristics of reception using digital beam forming. .

This has the effect of greatly increasing the detection distance. Furthermore, if the detection distance is made the same as that of conventional radar systems, the scale of the radar antenna can be significantly reduced, and a significant cost reduction effect can be expected.

[Brief explanation of drawings]

FIG. 1 is a diagram explaining the operation of radar snow removal according to an embodiment of the present invention, FIG. 2 is a diagram showing the structure of the antenna section of a conventional radar device, and FIG. 3 is a diagram showing the structure of the antenna section of a conventional radar device. FIG. 2 is a configuration diagram illustrating a signal flow. (1) is a conformal array antenna, +z+tll
building substrate, (51) to (3n) are elements, (41
) to (4n) are signal lines for controlling the phase shifter, (5) is a phase controller, (61) to (6n) are element antennas, (71)
- (7o) are transmission system signal lines. (8) is a microwave power divider, (91) to (9n
) is the receiving system signal line, aO is the digital beam forming circuit e ('h) ~ (Iln) is the transmitting/receiving switch, (+2
1) to (12n) Transmission system. (+51) to (+3n) are high power amplifiers e (“1)
~(14n) is a phase shifter, (+51)~(+5n) is a receiving system, (161)~(+6n) is a low noise amplifier e
(17t) to (17n) are analog-to-digital converters, and (+a,) to (184) are targets. (+91) to (194) are areas, (201) to (2
04) is a transmission beam, and (2h) to (21a) are reception beams. In addition, in FIG. 1, the same reference numerals indicate the same or corresponding parts. 1] ymi-marteshiichia> tena 181-184 Goal

Claims (1)

[Claims] A structural base having a given shape such as the surface of an aircraft or a ship, a plurality of element antennas arranged along the structural base, a phase shifter connected to each of the element antennas, and a high output power. A transmitting/receiving module including a transmitting section consisting of an amplifier, a low noise amplifier, a receiving system consisting of an analog-to-digital converter, and a transmitting/receiving switch, and a microwave power divider connected to the transmitting system of each transmitting/receiving module;
An antenna device comprising a transmitting beam controller connected to the phase shifter of each of the transmitting systems and a digital beam forming circuit connected to the receiving system of the transmitting/receiving module,
At the time of transmission, the plurality of element antennas of the antenna device are divided into a plurality of groups, and the phase of the phase shifter corresponding to each region is controlled so that the beams are directed in different directions for each divided group. Characteristic radar equipment.