JPH04110684A - Radar device - Google Patents

Abstract

PURPOSE:To enable frequency characteristics of a transmission peak power of radar to be compensated for and enable required power to be uniform by changing the number of transmission and reception modules which are used according to an operation frequency of radar. CONSTITUTION:The number of transmission and reception modules 3 is set according to control of a system control monitor circuit 10 and the system control monitor circuit 10 determines the number of used units so that transmission peak power is constant for the number of all transmission and reception modules within an array antenna 1, and then controls operation and non- operation of each transmission and reception module 3 through an array antenna control monitor circuit 9. With this configuration, it is possible to obtain a constant transmission peak power, namely a certain required power which does not depend on operation frequency.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a radar device using an active phased array antenna, and particularly to a radar device using an active phased array antenna. The present invention relates to a device having means for uniformly compensating the frequency characteristics of.

[Conventional technology]

Generally, an active phased array antenna is one in which a transmitting system or a receiving system is provided with active functional elements 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 frequency characteristics of the semiconductor element, the transmission peak power Pt as a radar has frequency characteristics.

Now, the transmission peak power Pt of one transmitting/receiving module as a transmission source is equal to the operating frequency f of the array antenna.
On the other hand, if the temperature characteristics were as shown in Fig. 4(a), in the conventional radar, all the transmitting and receiving modules incorporated in the array antenna were transmitting and receiving (the fourth Figure (b)), power required for radar W
Or, the frequency characteristic will be shown as shown in FIG. 4(C).

Here, Pto and Wo mean the transmission peak power and required power, respectively, corresponding to the center frequency fO.

Note that as for the temperature characteristics of the semiconductor power amplifier, in addition to the output power, the gain and efficiency temperature characteristics of the amplifier should also be considered, but these are omitted for the sake of simplifying the explanation. In addition, the following explanation will also be handled in the same manner.

[Problem to be solved by the invention]

As explained above, conventional radar equipment has extra radiated power, which increases power requirements and heat generation, which inevitably increases system cost. The drawback was that it radiated a lot of power.

The present invention has been made in order to eliminate the problems of conventional radar devices as described above, and an object of the present invention is to provide a radar device that can uniformly compensate for fluctuations in transmission peak power that vary depending on the operating frequency of the radar. It is an object.

[Means to solve the problem]

The radar device according to the present invention is configured such that the number of transmitting/receiving modules in the array antenna can be changed arbitrarily depending on the operating frequency.

[Effect]

In this invention, by having the configuration as described above, it is possible to obtain a constant transmission peak power, that is, a constant required power, regardless of the operating frequency.

〔Example〕

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

FIG. 1 shows a radar device according to an embodiment of the present invention,
FIG. 1(a) shows its overall configuration. In the figure, 1 is an active phased array antenna, 2 is an element antenna which is a radiating element of this array antenna l, and 3 is an active phased array antenna.
is a transmitting/receiving module for exciting the element antenna 2,
4 is a distributor that distributes the transmission signal to each transmission/reception module 3 and combines the reception signal; 5 is a transmission/reception switch for separating transmission and reception; 6 is a receiver; 7 is a transmission type signal generation circuit; 8 is a radar Stabilized local oscillator circuit (hereinafter referred to as 5TAL) that generates the reference signal of
9 is a control monitor circuit that controls the beam scanning of the array antenna 1, monitors its operation, and controls the number of transmitting/receiving modules, and 10 is a system control monitor circuit that controls the entire system. FIG. 1(b) is a block diagram of the transmitting/receiving module 3, in which 31 is a phase shifter for beam scanning, 32 is a circulator for separating transmitting and receiving signals, and 33 is a low-noise filter for amplifying the received signal. The amplifier 34 is a power amplifier that amplifies the transmitted signal.

The required power W of the radar depends on the transmission peak power P, that is, the transmission peak power P t (f+) of each transmitting/receiving module, so in order to make it independent of the frequency f, P=N- P t (f
), the number N of transceiver modules operating in the array antenna can be arbitrarily changed.

The number N of transmitting/receiving modules used is set under the control of the system control monitor circuit 10. Depending on the operating frequency f of the radar, the system control monitor circuit 10 calculates Pt for the total number of transmitting/receiving modules in the array antenna.
The number N to be used is determined so that the number N is constant, and the operation/inoperation of each transmitting/receiving module is controlled via the array antenna control/monitoring circuit 9.

FIG. 2 shows an example of frequency characteristic compensation according to the present invention.

In this way, according to the above embodiment, the frequency characteristics of the radar's transmission peak power are compensated by changing the number of transmitting and receiving modules used according to the operating frequency of the radar, so that the required power can be made uniform. Therefore, it is possible to obtain a low-cost radar device in which the amount of heat generated is kept to the necessary minimum.

In the above embodiment, the radar antenna is active.
Although a phased array antenna 1 is shown, in a conventional radar device in which the transmitter is installed outside the antenna, if the transmitter is composed of multiple power amplifiers as shown in Fig. 3, , the same effect as in the above embodiment can be obtained. In Fig. 3fa), 1 is an antenna, 2 is a transmitter/receiver switch for separating transmission and reception, 3 is a receiver, 4 is a transmitter, 5 is a 5TAL○ circuit that generates a reference signal for the radar, and 6 is a circuit for the entire system. This is a circuit that performs control and monitoring. Figure 3(b)
4 is a diagram showing the configuration of the transmitter 4, where 41 is a power amplifier that amplifies drive power, 42 is a power divider that distributes this drive power, and 43 is a plurality of power units for generating the required transmission peak power. An amplifier 44 is a power combiner that combines the powers of the power amplifier 43.

〔Effect of the invention〕

As described above, according to the present invention, the frequency characteristics of the transmission peak power of the radar are compensated for by changing the number of transmitting and receiving modules used according to the operating frequency of the radar, so that the required power can be uniformly reduced. There are benefits that can be obtained from a low-cost radar device.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram of a radar device according to an embodiment of the present invention;
FIG. 2 is a diagram showing an example of how the required power of a radar is equalized by the compensation method according to the present invention, FIG. 3 is a block diagram according to another embodiment of the present invention, and FIG. 4 is a diagram of a conventional radar device. FIG. 2 is a diagram showing frequency dependence of required power in FIG. In the figure, l is an active phased array antenna, 2 is an element antenna, 3 is a transmitter/receiver module, and 4 is an active phased array antenna.
5 is a transmitter/receiver switcher, 6 is a receiver, 7 is a transmission seed signal generation circuit, 8 is a 5TAL○ circuit, 9 is an array antenna control monitor circuit, and IO is a system section monitor circuit. In addition, in the figures, the same reference numerals indicate the same or corresponding parts.

Claims (1)

[Claims] (1) In a radar device using an active phased array antenna that performs beam scanning by exciting each of a plurality of arrayed element antennas with an excitation source with a predetermined phase difference, the excitation source is the transmitter and receiver. It is equipped with a means for controlling the number of modules used, and compensates the frequency characteristics of the radar transmission power generated by the frequency characteristics of the power amplifier in the transmission and reception module by the number of transmission and reception modules used, and reduces the transmission power and required power of the radar. A radar device characterized by uniformity.