JPH0262990A - Radar device - Google Patents

Abstract

PURPOSE:To compensate temperature variation in sent peak electric power by outputting a sent wave with optional sent pulse width and obtaining an optional pulse compression ratio. CONSTITUTION:A system control monitor circuit 11 controls a sent seed signal generating circuit 9 to generate a seed signal for pulse width according to the temperature signal of a temperature sensor 8 which is sent through an array antenna control monitor circuit 10. This seed signal is supplied to an expanded wave generating circuit 7 to generate an expanded wave, which is sent to a pulse compressing circuit 6 through a high frequency circuit 5. The pulse compression ratio at this time is also controlled by the circuit 11. Consequently, the temperature dependency of the required electric power of a radar can be compensated at an optional pulse compression ratio.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention is an active phased antenna that scans a beam by exciting each of a plurality of arrayed element antennas with an excitation source having a predetermined phase difference. The present invention relates to a radar device such as an active phased array radar using an array antenna, and particularly to a method for uniformly compensating for the temperature dependence of a power amplifier in a transmitting/receiving module.

[Conventional technology]

Generally active phased arrays such as those mentioned above
An active phased array antenna used in a radar stand has an active functional element in the transmitting system or the receiving system corresponding to each element antenna. Semiconductor elements such as bipolar transistors and field effect transistors are used as the active functional elements, and the transmitting system constitutes a high power amplifier and the receiving system constitutes a low noise amplifier.

When the transmission source of the active phased array antenna is composed of the above semiconductor power amplifier,
Because of the temperature characteristics of the semiconductor element, the transmission peak power pt as a radar has temperature characteristics. Now, if the transmission peak power pt has a temperature characteristic as shown in Fig. 5 (6) with respect to the operating temperature T of the array antenna, then
In conventional radar, the transmission pulse width P, that is, the compression ratio P
/τ was set constant regardless of the operating temperature (
Figure 5 (b)), the required power W for the radar is shown in Figure 5 (
It exhibits temperature characteristics as shown in C). In addition, in FIG. 5, Po, Pt, and wo are values at room temperature (about 20° C.).

As for the temperature characteristics of the semiconductor power amplifier, in addition to the output power, the temperature characteristics of the gain and efficiency of the amplifier should also be considered, but these are omitted to simplify the explanation. Further, the following explanation will also be handled in the same manner.

[Problem to be solved by the invention]

Conventional radar equipment has extra radiated power as explained above, which increases power requirements and heat generation, which inevitably increases system cost. The drawback was that it radiated electricity.

The present invention has been made in order to eliminate the problems of conventional radar devices as described above, and aims to provide a radar device that can compensate for fluctuations in transmission peak power that change depending on temperature. .

[Means to solve the problem]

The radar device according to the present invention is configured to output a transmission wave with an arbitrary transmission pulse width to obtain an arbitrary pulse compression ratio, thereby compensating for temperature fluctuations in transmission peak power.

(Function) In this invention, a transmission wave with an arbitrary transmission pulse width is output, an arbitrary pulse compression ratio is obtained, and temperature fluctuations in transmission peak power are compensated for. It is possible to obtain a low-cost radar device that is kept to a minimum.

〔Example〕

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

FIG. 1(a) shows the configuration of an active phased array radar according to an embodiment of the present invention.
is an active phased array antenna, 2 is an element antenna which is a radiating element of this array antenna 1,
3 is a transmitter/receiver module for exciting the element antenna 2; 4 is a distributor that distributes the transmitting type signal to each transmitter/receiver module 3 and synthesizes the received signal; 5 is a high frequency circuit for transmitting and receiving; 6 is a transmitter for receiving signals; 7 is a pulse compression circuit; 7 is a transmission pulse expansion wave generation circuit; 8 is a transmission seed signal generation circuit; 9 is a temperature sensor that monitors the operating temperature inside the array antenna 1; 10 is a beam scanning control for the array antenna 1; 11 is a system control monitor circuit that controls and monitors the entire system.

FIG. 1(b) is a configuration diagram of the transmitter/receiver module 3, in which 31 is a phase shifter for beam scanning, 32 is a circulator for transmitting and receiving separation, and 33 is a low noise filter for amplifying the received signal. The amplifier 34 is a power amplifier that amplifies the transmission signal.

Since the radar required power W depends on the transmission peak power pt, in order to make it independent of the temperature T, the transmission pulse width P (that is, the pulse compression ratio P/τ). Here, Po and Pto are values at room temperature (about 20° C.). The radar transmission pulse width P is set under the control of the system control monitor circuit 11. Array antenna control monitor circuit 1
In response to the temperature signal from the temperature sensor 9 sent from the temperature sensor 9, the system control monitor circuit 11 instructs the transmission seed signal generation circuit 8 to generate a seed signal with a pulse width P expressed by the above equation (11). (dashed line signal in FIG. 2(a)).

This kind of signal passes through the expanded wave generation circuit 7, as shown in FIG. 2(b).
It becomes an expanded wave (signal indicated by a broken line) as shown in FIG.

Then, the pulse is compressed into a pulse with a constant pulse width as shown in FIG. 2(C) and sent to the subsequent circuit. The pulse compression ratio P/τ at this time is also controlled by the system control monitor circuit 11 so as to satisfy the above equation. By doing so, it becomes possible to compensate for the temperature dependence of the required power W of the radar with an arbitrary pulse compression ratio.

FIG. 3 shows an example of the temperature compensation according to the present invention.

In the above embodiment, the radar antenna is an active phased array antenna 1 that includes a transmitting/receiving module 3, and a temperature sensor 9 is provided therein, but the transmitter can be moved outside the antenna. If the provided radar device has the configuration shown in the other embodiment of the present invention shown in FIG. 4, the same effects as in the above embodiment can be obtained.

In FIG. 4, 21 is an antenna, 22 is a transmitting/receiving switch for separating transmission and reception, 23 is a receiver, 24 is a pulse compression circuit for the received signal, 25 is a transmitter, 26 is an expanded wave generation circuit for the transmitted pulse, and 27 is a A transmission type signal generation circuit; 28 a system control circuit for controlling and monitoring the entire system; 29;
is a temperature sensor that monitors the operating temperature of the transmitter 5.

〔Effect of the invention〕

As described above, according to the radar device according to the present invention, the temperature characteristics of the radar transmission peak power are compensated by an arbitrary pulse compression ratio, so that the heat generation amount and the required power are kept to the necessary minimum. This has the effect of providing a low-cost radar device.

[Brief explanation of the drawing]

2(a), (b), and (C) respectively show the seed signal generated by the transmission seed signal generation circuit 7, the transmission wave radiated from the antenna 1, and the pulse-compressed video waveform. 3 is a diagram showing an example of the operation of equalizing the required power of the radar by the compensation method of the above embodiment, FIG. 4 is a block diagram of another embodiment of the present invention, and FIG. 5 is a diagram of the conventional FIG. 2 is a diagram showing the temperature dependence of required power in a radar device. In the figure, 1 is an active phased array antenna, 2 is an element antenna, 3 is a transmitting/receiving module, 4 is a distributor, 5 is a high frequency circuit, 6 is a pulse compression circuit, 7 is an expanded wave generation circuit, and 8 is a transmission seed signal. a generation circuit, 9 a temperature sensor, 10 a control monitor circuit, 11 a system control circuit,
21 is an antenna, 22 is a transmitting/receiving switch, 23 is a receiver, 2
4 is a pulse compression circuit, 25 is a transmitter, 26 is an expanded wave generation circuit, 27 is a transmission type signal generation circuit, 28 is a system control circuit, 29 is a temperature sensor, 31 is a phase shifter, 32 is a circulator, 33 is a low The noise amplifier 34 is a power amplifier. Note that the same reference numerals in the figures indicate the same or equivalent parts. (a) Figure 1

Claims (1)

[Claims] (1) In a radar device, there is a radar transmission pulse width setting means for outputting a transmission wave with an arbitrary transmission pulse width, a pulse compression means for performing pulse compression processing on the received wave, and a controller in the transmitter to equalize the power required for the radar. A radar device comprising temperature characteristic compensating means for compensating for the temperature characteristic of the power amplifier by changing a pulse compression ratio.