JPS6018784A - Homing apparatus - Google Patents

Abstract

PURPOSE:To stabilize the catching and tracking of a target in any guide mode by making transmission/reception frequency in an active homing guide mode higher than that in a semi-active homing guide mode. CONSTITUTION:As a target approaches at a specified distance, a target distance detector 7 transmits a switching signal to a switch controller 8 to switch the tracking system to the active homing guide from the semi-active homing guide to operate a transmitter 9 of the frequency f2 thereby switching the received frequency f1 of a receiver 3 to f2. With a switch over to a high frequency f2, the beam width is reduced to increase the antenna gain resulting in a higher S/N ratio and an improved lock-on probability. Then, suc a higher S/N ratio can enhance the gain in the tracking loop to improve the response to a quick turning of a target.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a homing device, and more particularly to a missile-mounted homing device that has two guidance modes: semi-active homing guidance in intermediate guidance and active homing guidance in terminal guidance.

Conventional homing devices of this type use the same frequency for semi-active homing guidance and active homing guidance. and.

To facilitate initial target detection and acquisition during semi-active homing guidance, the antenna beam width is widened and
The antenna gain should be low. Even though the antenna gain is low in this way, in semi-active homing, the shortcomings of the antenna's low gain are compensated for by making the output of the ground irradiation device that emits radio waves to the target large enough to shorten the required lock-on distance. I was getting it.

As the distance between the target and the missile gradually decreases, the guidance mode is switched to active homing. As the distance between the target and the missile decreases in this way, the angular velocity of the missile's line of sight when looking at the target increases. Therefore, in order to sufficiently track the movement of the target, it is necessary to increase the loop gain of the tracking system and obtain a sufficient S/N ratio of the target signal. However, since the conventional homing device uses all the same frequencies for semi-active homing guidance and active homing guidance, the same low antenna gain remains for active homing guidance as for semi-active homing guidance. Therefore, when the antenna gain, loop gain, and S/N ratio necessary for stable acquisition and tracking of the target are not obtained in short-range tracking, and the target makes rapid joint movements, the homing device cannot fully follow the target. The drawback was that it missed its target.

An object of the present invention is to provide a homing device that can stably capture and track a target in both semi-active homing and active homing guidance modes.

The configuration of the present invention has two guidance modes, semi-active homing and active homing, and an antenna that receives all the reflected radio waves of a target object and tracks the target object is used in both of the guidance modes. It is characterized in that the transmission and reception frequency in the guidance mode is higher than the reception frequency in the semi-active homing guidance mode.

In the present invention, the reception frequency band during semi-active homing guidance is set to fl, and the transmission and reception frequency band during active homing guidance is set to f2, which is higher than fl, so that they are different from each other. And 1 Usually, f2 is f□! l
More than 12 times higher, these frequencies are in two different frequency bands. The antenna gain G and beam width θ are expressed by the following equations.

G-(πD/λ)η (1) θ~70λ/D (2) η: Antenna efficiency, ■〕: Antenna diameter, λ: Wavelength. This shows that the antenna can be made narrower and the antenna gain can be improved. Therefore, according to the present invention, in active homing guidance, by using a sufficiently high frequency for semi-active homing guidance, stable and highly accurate capture and tracking is possible in any guidance mode. Homing device can be provided.

The invention will now be described in detail with reference to Figure f.

FIG. 1 is a block diagram of one embodiment of the present invention.

A target reflected wave of a radio wave (frequency f□) emitted from a ground radar is received by the missile-mounted antenna 1.

The received wave passes through two transmitter/receiver switchers and is outputted as a target signal by the receiver 3. A part of the target signal is converted by the error angle detector 4 into an angle signal indicating the error angle between the antenna axis and the target direction, and further amplified by the servo amplifier 5 and sent to the torquer 6. The torquer 6 drives the antenna 1 so that the target is always on the 111 line of the antenna 1, and tracks the target. Moreover, the target distance detector 7 is.

It is connected to the receiver 3 and measures the distance to the target from the reception strength of the target signal or the arrival time of the signal wave. When the target approaches to a predetermined distance, the target distance detector 7 sends a signal to the switching controller 8 for switching the entire tracking system from semi-active homing guidance to active homing guidance.

The switching controller 8 operates the transmitter 9 at the frequency f2 and sends an activation signal for switching the receiving frequency of the receiver 3 from f□ to f2.

51 In this embodiment, when the tracking system switches to active homing guidance, it switches from the frequency If□ to a higher band f2, thereby narrowing the beam width and at the same time increasing the antenna gain, improving the S/N ratio, and lock-on. The aim is to improve the probability. Since the improved S/N ratio allows the gain of the tracking loop to be increased, the response to rapid joint movements of the target is also significantly improved.

As explained above, the present invention can achieve a
Stable tracking is achieved by increasing the antenna gain, improving the S/N ratio and lock-on probability in active homing guidance, which was difficult with conventional devices that use the same frequency in both guidance modes, and significantly improving guidance accuracy. Homing device can be provided. Furthermore, the present invention is easy to combine with a conventional ground irradiation device, and the frequency for active homing guidance is lower than the frequency for semi-active homing guidance (for example, the X band). By setting it very high (for example, Nimata←iKa band),
It is possible to miniaturize the components, mount the transceiver on the gimbal, miniaturize the antenna, significantly reduce power consumption, eliminate redundant signal lines, and reduce noise, making it possible to homing for missile installation in small eaves. Equipment can be provided.

[Brief explanation of drawings]

FIG. 1 is a block diagram of one embodiment of the present invention. 1... Antenna, 2... Transmission/reception switch,
3...Receiver, 4...Error angle detector,
5... Servo amplifier. 6...Toruka, 7...1] Target range detector, 8...Semi-active homing/active homing switching controller, 9...Transmitter. 7-1

Claims (1)

[Claims] In a homing device that has two guidance modes, semi-active homing and active homing, and which receives reflected radio waves from a target object and tracks the target object, the transmitting and receiving frequency in the active homing guidance mode is A homing device characterized in that the receiving frequency is higher than that in a semi-active homing guidance mode.