JPH03209904A - Electronic scanning antenna - Google Patents

Abstract

PURPOSE:To make a beam scan in the same direction at the time of transmission and reception without being affected by the influence of the noninreversibility of a phase shifter by providing TR switches in front of and behind the phase shifter so that a high frequency signal is inputted in the determined direction of the phase shifter. CONSTITUTION:At the time of transmitting, the high frequency signal which is generated by an exciter 6 passes through the TR switch 5 and is distributed by a feeding circuit 4 to respective transmission and reception modules 2a-2n and the phase shifter 21 sets phase shift quantities with a control signal according to the array order of the elements 1a-1n. The phase-shifted high frequency signal passes through the TR switch 28, and through a high output amplifier 22 and the TR switch 24 and is radiated into the air from antennas 1a-1n. A reflected light from a target is inputted to the phase shifter 21 through the switch 24, low-noise amplifier 23, and a TR switch 29. The nonreversibility of the phase shifter 21 can be removed to make the beam scan in the direction with the transmission.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an electronic scanning antenna constituted by a plurality of transmitting/receiving modules.

[Conventional technology]

Fig. 3 is a diagram showing a conventional electronic scanning antenna. In Fig. 2, (Ia) to (1n) are element antennas, (2
a) to (2n) are transmitting/receiving modules, and (3) is a phase shift control circuit.

(4) is a power supply circuit, (5) is a transmission/reception switch, and (6) is an exciter.

(7) is a receiver. FIG. 4 is a diagram showing one of the transmitting/receiving modules (2a) to (2n) used in this electronic scanning antenna. In FIG. 2, (1) is an element antenna, (21) is a phase shifter, (22) ) is a high-power amplifier, (23) is a low-noise amplifier, (24), (2
5) is a transmitter/receiver switch.

This electronic scanning antenna sends a phase shift control signal from a phase shift control circuit (3) to a phase shifter (21), and each element antenna (1a
) to (1n), the amount of phase shift of the phase shifter (21) is changed numerically between -order (dotted line) as shown in Fig. 5 (A).
The beam direction θ is controlled as shown in FIG. 5(B).

(2) [Problem to be solved by the invention] In the conventional electronic scanning antenna as described above, phase shift control for beam scanning is performed by calculating the amount of phase shift using a processor in the phase shift control circuit (3). Transmission/reception module (2a) ~ (
Each phase shift amount of the phase shifter (21) in the phase shifter (2n) is controlled by a phase shift control signal. Further, as shown in FIG. 4, a high frequency signal is input from the right side of the phase shifter (21) during transmission, and conversely, a high frequency signal is input from the left side of the phase shifter (21) during reception. Therefore, since the direction of the high-frequency signal passing through the phase shifter (21) is different during transmission and reception, the phase shifter (21) is shifted between transmission and reception due to the irreversibility of the phase shifter (21). There was a problem in that the amount of phase was different, resulting in a difference in beam scanning direction during transmission and reception.

On the other hand, in order to prevent deviations in the beam scanning direction due to the irreversibility of the phase shifter (21), there are methods to have separate phase shifters in the transmitting system and receiving system, and a phase shift control circuit (3). There is a method in which the phase shift amounts during transmission and reception are calculated separately by a processor within the receiver, taking into account the irreversibility of the phase shifter (21). However, this method has disadvantages in that the dimensions of the transmitter/receiver module (3) become larger and that it takes twice as long to calculate the amount of phase shift.

This invention was made to solve the above-mentioned problems, and the purpose is to obtain an electronic scanning antenna that can scan beams in the same direction for transmission and reception without being affected by the irreversibility of the phase shifter. shall be.

[Means to solve the problem]

The electronic scanning antenna according to the present invention has the same beam scanning direction regardless of whether it is transmitting or receiving.

Transmission/reception changeover switches are provided before and after the phase shifter so that high-frequency signals are input from a predetermined direction of the phase shifter.

[For production]

The electronic scanning antenna of the present invention is switched by a transmission/reception switch provided before and after the phase shifter so that the high-frequency signal is input from a predetermined direction of the phase shifter regardless of whether it is transmitting or receiving, so it is difficult to increase the size of the device. This eliminates the irreversibility of the phase shifter.

〔Example〕

(4) FIG. 1 is a diagram showing an embodiment of the present invention.

In the figure, (la) to (1n) are element antennas,
(2a) to (2n) are transmitting/receiving modules, (3) is a phase shift control circuit, (4) is a power supply circuit, (5) is a transmitting/receiving switch,
(6) is an exciter, (7) is a receiver, and (8) is a transmission/reception switching control circuit. FIG. 2 is a configuration diagram showing one of the transmitting/receiving modules (2a) to (2n) used in an embodiment of the present invention.

(1) is the element antenna in Fig. 1, (21) is the phase shifter,
(22) is a high output amplifier, (23) is a low noise amplifier, (24) is a transmitter/receiver switch, (28), (29)
is a transmit/receive switch.

In Figure 1, during transmission, high frequency signals such as microwaves generated by the exciter (6) pass through the transmitter/receiver switch (5) and are distributed to each transmitter/receiver module (2a) to (2n) by the power supply circuit (4). The phase shift amount according to the arrangement order of the element antennas (1a) to (1n) is set by the phase shift control signal in the phase shifter (21) shown in FIG. The high frequency signal that has undergone the phase shift passes through the transmission/reception selector switch (28) and is sent to the high output amplifier (28).
2) is amplified and switching between transmission and reception! ! ! ! (24) and is radiated into space from each element antenna (1a) to (1n).

On the other hand, the high-frequency signal reflected from the target passes through the transmitter/receiver switcher (24) and the low-noise amplifier (reversely to the transmission (5)).
23), the signal passes through a transmission/reception switch (29) which is switched by a transmission/reception switching control signal, and is input to the phase shifter (21) from the same direction as when transmitting. Therefore.

The phase shift amount of the phase shifter (21) during reception is the same as that during transmission, and the irreversibility of the phase shifter (21) can be removed, and the beam scanning direction becomes the same direction as during transmission.

In this way, the transmission/reception switch (28) is used when transmitting.

Using (29), the phase of the high-frequency signal is shifted from the same direction as during transmission! (21) by switching to input.

without being affected by the irreversibility of phase shift 1 (21).

Antenna beams can be sent and received easily and scanned in the same direction.

In the above description, the case where the element antennas are arranged linearly is described, but the same applies to the case where the element antennas are arranged biplanarly.

Further, although the case of an active method using a high-output amplifier and a low-noise amplifier in the transmitting/receiving module has been described, the present invention can be similarly applied to a case of a passive method that does not use a high-output amplifier or a low-noise amplifier.

(6) [Effects of the Invention] As described above, according to the present invention, high-frequency signals are always sent from the same direction to the phase shifter in the transmitter/receiver module constituting the electronic scanning antenna by using the receiver changeover switch. By eliminating the irreversibility of the phase shifter switched to input,
This has the effect of providing an electronic scanning antenna that can accurately transmit and receive antenna beams to scan in the same direction without increasing the size of the device.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing an embodiment of an electronic scanning antenna according to the present invention, FIG. 2 is a configuration diagram of a transmitting/receiving module used in the present invention, FIG. 3 is a schematic diagram showing a conventional electronic scanning antenna, and FIG. The figure is a configuration diagram of a transmitting/receiving module used in a conventional antenna. FIG. 5 explains this directional characteristic. FIG. 5(A) is a chart showing the amount of phase shift of each phase shifter, and FIG. 5(B) is a directional characteristic diagram of the electronic scanning antenna. In the figure, (Ia) to (1n) are element antennas, (2a)
) to (2n) are transmitting/receiving modules, (3) is a phase shift control circuit, (4) is a supply (7) main circuit, (5) is a transmitting/receiving switch, (6) is an exciter, (7)
) is a receiver, (8) is a transmission/reception switching control circuit, (21) is a phase shifter, and (28). (29) is a transmission/reception changeover switch. Note that the same or corresponding parts in the two figures are designated by the same reference numerals.

Claims (1)

[Claims] It is equipped with a plurality of element antennas, a plurality of transmitter/receiver modules provided in each of the plurality of element antennas, and a phase shift control circuit that provides a phase shift control signal corresponding to the beam direction to the transmitter/receiver module. In an electronic scanning antenna in which the main beam direction is controlled by producing a required amount of phase deviation in the high-frequency signal that is being received, in order to accurately scan the antenna beam in the same direction during transmission and reception, there is a A transmission/reception selector switch is provided before and after the phase shifter so that the input end and output end of the phase shifter are in the same direction during transmission and reception, and high frequency signals are always transmitted from the specified direction of the phase shifter regardless of transmission and reception. An electronic scanning antenna characterized by comprising a transmission/reception switching control circuit that applies a transmission/reception switching control signal to the transmission/reception switching switch so that a signal is input.