JPH073925B2 - Electronic scanning antenna - Google Patents

Description

The present invention relates to an electronic scanning antenna including a plurality of transmitting / receiving modules.

[Conventional technology]

FIG. 3 is a diagram showing a conventional electronic scanning antenna, in which (1a) to (1n) are element antennas and (2a) to (2
n) is a transceiver module, (3) is a phase shift control circuit,
(4) is a power supply circuit, (5) is a transmission / reception switch, (6) is an exciter, and (7) is a receiver. FIG. 4 is a diagram showing one of the transceiver modules (2a) to (2n) used in this electronic scanning antenna, in which (1) is an element antenna, (21) is a phase shifter, and (22) ) Is a high power amplifier,
(23) is a low noise amplifier, and (24) and (25) are duplexers.

This electronic scanning antenna sends a phase shift control signal from the phase shift control circuit (3) to the phase shifter (21), and each element antenna (1a)-
According to the arrangement order of (1n), each phase shift amount of the phase shifter (21) is set so as to make a linear function change (dotted line) as shown in FIG. The beam direction θ is controlled as described above.

[Problems to be Solved by the Invention]

In the conventional electronic scanning antenna as described above, the phase shift control for beam scanning is performed by calculating the amount of phase shift using the processor in the phase shift control circuit (3) and transmitting / receiving modules (2a) to (2).
Each phase shift amount of the phase shifter (21) in n) is controlled by the 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 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) shifts during transmission and reception due to the irreversibility of the phase shifter (21). There was a problem that the phase amount was different, resulting in a difference in the beam scanning direction during transmission and reception.

On the other hand, in order to prevent the deviation in the beam scanning direction due to the non-reciprocity of the phase shifter (21), a method and a phase shift control circuit (3) in which the phase shifter is provided separately for the transmission system and the reception system There is a method of calculating the amount of phase shift at the time of transmission and the amount of phase shift at the time of reception separately in the processor in consideration of the irreversibility of the phase shifter (21). However, this method has the disadvantages that the size of the transmission / reception module becomes large and that the calculation of the amount of phase shift takes time (twice).

The present invention has been made to solve the above problems, and an object thereof is to obtain an electronic scanning antenna capable of beam scanning in the same direction for transmission and reception without being affected by the irreversibility of a phase shifter. And

[Means for Solving the Problems]

In the electronic scanning antenna according to the present invention, the beam scanning direction is the same regardless of transmission / reception. Therefore, a transmission / reception changeover switch is provided in front of and behind the phase shifter so that a high frequency signal is input from a predetermined direction of the phase shifter. It is a thing.

[Work]

Since the electronic scanning antenna according to the present invention is switched by the transmission / reception change-over switch provided before and after the phase shifter so that the high frequency signal is input from the determined direction of the phase shifter regardless of transmission / reception, the size of the device can be increased. Without, the irreversibility of the phase shifter can be eliminated.

〔Example〕

FIG. 1 is a diagram showing an embodiment of the present invention, in which (1a) to (1n) are element antennas, (2a) to (2n) are transceiver modules, (3) is a phase shift control circuit, (4) is a power supply circuit, (5) is a transmission / reception switch, (6) is an exciter,
(7) is a receiver, and (8) is a transmission / reception switching control circuit. FIG. 2 is a block diagram showing one of the transmitting / receiving modules (2a) to (2n) used in one embodiment of the present invention,
(1) is the element antenna of FIG. 1, (21) is a phase shifter, and (2)
2) is a high output amplifier, (23) is a low noise amplifier, (24) is a transmission / reception selector, and (28) and (29) are transmission / reception selector switches.

In Fig. 1, during transmission, high-frequency signals such as microwaves generated by the exciter (6) are distributed to the transmission / reception modules (2a) to (2n) through the transmission / reception switch (5) and the power supply circuit (4). The phase shifter (21) shown in FIG.
The amount of phase shift according to the arrangement order of (1n) is set by the phase shift control signal. The high-frequency signal that has undergone the phase shift is passed through the transmission / reception switch (28), amplified by the high output amplifier (22), and passed through the transmission / reception switch (24) to each element antenna (1a).
~ (1n) radiates into space.

On the other hand, the high frequency signal reflected from the target passes through the transmission / reception switching device (24), is amplified by the low noise amplifier (23), and then is switched by the transmission / reception switching control signal. 29), and is input to the phase shifter (21) from the same direction as during transmission. Therefore, the amount of phase shift of the phase shifter (21) at the time of reception is the same as that at the time of transmission, the irreversibility of the phase shifter (21) can be eliminated, and the beam scanning direction becomes the same direction as at the time of transmission.

In this way, the transmission / reception changeover switches (28), (29) during transmission
The high-frequency signal is transmitted from the same direction as the phase shifter (2
By switching to input to 1), the phase shifter (21)
The antenna beam can be accurately scanned in the same direction for transmission and reception without being affected by the irreversibility of.

In the above description, the case where the element antennas are arranged linearly has been described, but the same can be applied to the case where the element antennas are arranged linearly.

In addition, the active system using high-power amplifiers and low-noise amplifiers in the transceiver module was described, but the same can be applied to the passive system that does not use high-power amplifiers or low-noise amplifiers.

〔The invention's effect〕

As described above, according to the present invention, the phase shifter in the transmission / reception module constituting the electronic scanning antenna is configured so that the high frequency signal is always input to the phase shifter from the same direction by using the transmission / reception changeover switch. By removing the reversibility,
There is an effect that it is possible to provide an electronic scanning antenna that can accurately scan an antenna beam in transmission and reception in the same direction without increasing the size of the device.

[Brief description of drawings]

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 block diagram of a transmitting / receiving module used for a conventional antenna, and FIG. 5 is a diagram for explaining this directional characteristic. The figure (A) is a chart showing the amount of phase shift of each phase shifter, and the figure (B) is It is a directional characteristic figure of an electronic scanning antenna. In the figure, (1a) to (1n) are element antennas, and (2a) to (2n)
Is a transmission / reception module, (3) is a phase shift control circuit, (4) is a power supply circuit, (5) is a transmission / reception switcher, (6) is an exciter,
(7) is a receiver, (8) is a transmission / reception switching control circuit, (21) is a phase shifter, and (28) and (29) are transmission / reception switching switches. In the drawings, the same or corresponding parts are designated by the same reference numerals.

Claims (1)

[Claims] 1. An exciter comprising a plurality of element antennas, a plurality of transmission / reception modules provided in each of the plurality of element antennas, and a phase shift control circuit for giving a phase shift control signal corresponding to the beam direction to the transmission / reception modules. To accurately scan the antenna beam during transmission and reception in an electronic scanning antenna that controls the main beam direction by producing a required amount of phase shift in the high-frequency signal sent from the detector A transmission / reception changeover switch is provided before and after this phase shifter so that the input end and the output end of the phase shifter in the transmission / reception module are in the same direction during transmission and reception, and the phase shifter is defined regardless of transmission / reception. The electronic scanning device is provided with a transmission / reception switching control circuit for giving a transmission / reception switching control signal to the transmission / reception switching switch so that a high-frequency signal is always input from the same direction. Tena.