JPH0244225Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a radar device mounted on a flying object or the like.

First, a conventional radar device of this type shown in FIG. 1 will be explained.

It is assumed that an antenna 2 and a radar transmitting/receiving device 3 are provided inside the flying object 1, and 3 also includes a signal processing device. Radio waves generated by the radar transmitting/receiving device 3 are radiated to the outside space from the antenna 2, and echoes reflected by the target are received by the radar transmitting/receiving device 3 via the antenna 2 again.

Incidentally, this type of flying object is a threat to the other party, and the other party also uses radar or the like to detect it early.

Furthermore, there are even attempts to destroy radar receivers by utilizing the radio wave focusing function of radar antennas mounted on flying objects and emitting powerful radio waves towards these antennas. Recently, a technique has been proposed in which the surface of a flying object is covered with a radio wave absorber or the like to protect it from being detected by an opponent's radar or the like. However, even if the body of the aircraft such as a flying object can be covered with a radio wave absorber, the antenna opening, which must transmit and receive its own radio waves, cannot be covered with a radio wave absorber, and it is completely exposed to the radar of the other party. I couldn't escape from the net. Furthermore, the antenna usually faces the other party, and the effective scattering cross section is large, and this drawback of the prior art has greatly hindered the practical application of this type of technology.

This invention solves these drawbacks by attaching a radio wave absorber that can be opened and closed in front of the antenna.This invention will be explained in detail below with reference to the drawings.

Figure 2 shows an embodiment of this invention, showing the antenna 2.
A radio wave absorber 4 that can be opened and closed is attached to the front of the flying body 1, and the radio wave absorber 4 is opened as shown by the broken line only when the radar transmitter/receiver 3 inside the flying object 1 is activated, and the radio wave absorber 4 is opened as shown by the broken line when the radar transmitter/receiver 3 is not activated. It is assumed that the absorber 4 is closed as shown by the solid line.
By doing so, the probability of being found by other radar devices can be reduced.
A specific example of opening and closing the radio wave absorber is shown in FIG.

In FIG. 3, it is assumed that the trigger signal 7 is input to the electromagnetic switch control device 6. A timing diagram at this time is shown in FIG. It is assumed that A in FIG. 4 is a trigger signal 7, and this trigger signal causes the electromagnetic switch control device 6 to generate a signal shown in B. The signal shown in FIG. 3 is input to the transmission control device 5 and the electromagnetic switch 8 in FIG. In the transmission control device 5, the transmission control pulse is output after a slight delay as shown in FIG. 4C after the signal (b) is input, and ends slightly earlier than the end of the signal (b).

On the other hand, while the signal B continues, the electromagnetic switch 8
It is assumed that the radio wave absorber 4 can be opened by operating the radio wave absorber 4. While the signal shown in FIG. 4C generated by the transmission control device 5 continues, the radar transmitting/receiving device is operated.

By doing as described above, radio waves can be transmitted and received from the radar transmitting/receiving device 3 only while the radio wave absorber 4 is open.

As described above, in the radar device according to this invention,
A movable radio wave absorber that is moved by a switch is installed in front of the antenna, and the transmitter/receiver is activated to radiate radio waves to the space outside the spacecraft.When receiving echoes reflected by the target, the radio wave absorber is opened. Since the switch is equipped with a switching control device that controls the switch to close the radio wave absorber when the transmitting/receiving device is not in operation, it is possible to cover the antenna with a large effective scattering cross section with the radio wave absorber, making it difficult for other radars to operate. This has the effect of making it difficult to be searched.

Although the above is only for the case of radio waves,
It should be noted that the present invention can also be applied to light wave radars using lasers and the like.

[Brief explanation of drawings]

Figure 1 is a diagram showing a conventional radar device installed in a flying body, Figure 2 is a diagram showing an embodiment of the radar device according to this invention attached to a flying body, and Figure 3 is a diagram showing details of opening and closing of the radio wave absorber. FIG. 4 is a diagram showing the timing of opening and closing of the radio wave absorber. In the figure, 1 is a flying body, 2 is an antenna, 3 is a radar transmitting/receiving device, 4 is a radio wave absorber, 5 is a transmission control device, 6 is an electromagnetic switch control device, 7 is a trigger signal, 8 is an electromagnetic switch, A is the trigger signal time waveform,
B is the time waveform of the control signal output from the electromagnetic switch control device, and C is the time waveform of the control signal output from the transmission control device. It should be noted that the same or corresponding parts in the figures are indicated by the same reference numerals.

Claims (1)

[Scope of utility model registration request] A radar device that is mounted on a spacecraft and includes an antenna that emits radio waves into a space outside the spacecraft and receives echoes reflected by a target, and a transmitting and receiving device connected to this antenna. A movable radio wave absorber installed on the front,
A switch that moves the radio wave absorber and the transmitter/receiver are activated to radiate radio waves into the external space of the spacecraft, and when receiving echoes reflected by the target, the radio wave absorber is opened and the transmitter/receiver is activated. and a switching control device that controls the switch to close the radio wave absorber when the radio wave absorber is not operated.