JP2748502B2 - Radar equipment - Google Patents

Description

Description: BACKGROUND OF THE INVENTION (Industrial application field) The present invention relates to a long-short and complex pulse type radar apparatus, and more particularly to an improvement of an azimuth blanking function adapted to a radio wave environment in a surrounding area where the radar apparatus is installed.

(Prior Art) In recent years, the number of cases in which a pulse compression method is adopted in radar apparatuses for the purpose of higher performance and higher functionality has increased.
With the pulse compression method, instead of transmitting with a high output short pulse, a specially modulated low output long pulse is transmitted, the pulse width is compressed by correlation processing after reception, and the pulse amplitude is accumulated, and the pulse amplitude is accumulated. It is well known as a method that can achieve a required resolution while securing it.

However, in the pulse compression method, if the pulse width of the transmission signal is increased, the reception sensitivity is suppressed during transmission, and thus there is a disadvantage that the minimum detection distance is increased. For this reason, as a method that does not degrade the short-range detection performance and makes use of the features of the pulse compression method, a long and short composite pulse method has been considered and put to practical use.

On the other hand, a radar apparatus usually has an azimuth blanking function for adapting to the radio wave environment in the surrounding area. Therefore, a conventional radar device using a long and short composite pulse is configured as shown in FIG. 3, for example.

In FIG. 3, the radar apparatus includes a short pulse transmission signal generation system 1, a long pulse transmission signal generation system 2, and a corresponding short pulse reception system 9 and long pulse reception system 10,
Prior to transmission and reception of the pulse compression transmission signal (long pulse transmission signal), transmission and reception of the short pulse transmission signal are performed, and as shown in FIG. Main bank of the pulse transmission signal (main bang:
(A section corresponding to the pulse width) to obtain a short-range coverage in which the reception sensitivity is suppressed by a short pulse transmission signal.

More specifically, the transmission signals generated by the short-pulse transmission signal generation system 1 and the long-pulse transmission signal generation system 2 are combined in the synthesizer 3 such that the short-pulse transmission signal is placed before the long-pulse transmission signal. The composite pulse transmission signal having a long and short time relationship as shown in FIG. 4 (b) is amplified to a required power level by the transmitter 4 via the gate circuit 14, and transmitted from the antenna 6 via the circulator 5. You.

The signal received by the antenna 6 (FIG. 4 (d)) is amplified by a low noise amplifier 7 via a circulator 5 and then guided to a switch 8. This switch 8 is controlled by a control signal b
Accordingly, the short-distance received signal is switched to the short-pulse receiving system 9 and the long-distance received signal is switched to the long-pulse receiving system 10, and the switching point corresponds to the distance at which the reception sensitivity suppression occurs, that is, substantially the long pulse width. Set to distance. Then, the signals amplified and detected by the respective receiving systems are combined by adjusting the timing and the level by the combiner 11 (FIG. 4 (e)), and output as reception outputs outside the figure.

As a result, when azimuth blanking is not applied, as shown in FIG. 4A, the short-range coverage is a short-pulse transmission signal, and the long-range coverage is a long-pulse transmission signal. Is obtained.

When the azimuth blanking region is formed in a required azimuth range within the radar coverage area as shown in FIG. 5 (a), the azimuth blanking region corresponds to the azimuth blanking region as shown in FIG. 5 (b). The azimuth blanking control signal a, which is low in the time section, is applied to the gate circuit 14, so that transmission is not performed in the section in which the azimuth blanking control signal a is low (FIG. 5 (c)). ).

(Problems to be Solved by the Invention) However, in the conventional azimuth blanking method, as described above, the short pulse transmission signal and the long pulse transmission signal which are transmission signals in a specific azimuth range are all cut off uniformly. ,
There is a problem that the function of the radar device is completely lost in the azimuth range.

The present invention has been made in view of such problems,
It is an object of the present invention to provide a radar apparatus which pays attention to the features of the long and short composite pulse system and does not impair the original purpose of azimuth blanking and can prevent loss of radar detection characteristics due to azimuth blanking.

(Means for Solving the Problems) In order to achieve the above object, a radar device of the present invention has the following configuration.

That is, the radar apparatus of the present invention includes a short-pulse transmission signal generation system and a long-pulse transmission signal generation system, and a long-short composite pulse type radar apparatus that transmits a short pulse transmission signal before a long pulse transmission signal. A first control circuit for receiving the first control signal and stopping the operation of the short pulse transmission signal generation system for a predetermined period; and receiving the second control signal to stop the operation of the long pulse transmission signal generation system for a predetermined period. A second control circuit for stopping the operation; and an azimuth blanking control circuit for independently generating the first and second control signals in a predetermined azimuth range.

(Operation) Next, the operation of the radar apparatus of the present invention configured as described above will be described.

In the present invention, the short pulse transmission signal generation system and the long pulse transmission signal generation system can be independently controlled to stop, so that in addition to the conventional method of applying the same azimuth blanking to both long and short pulse transmission signals, The azimuth blanking is applied only to the long pulse transmission signal, and the detection function can be maintained with the short pulse transmission signal.

Normally, azimuth blanking is performed for the purpose of preventing a radio signal from interfering with peripheral devices due to a transmission signal of a radar device. However, the effect of the transmission signal on peripheral devices is considered to be proportional to the transmission power. Then, since the transmission power is proportional to the pulse width, it can be considered that, when only the short pulse transmission signal is transmitted, the average power is extremely low and the influence on the peripheral device is not great.

Therefore, according to the radar apparatus of the present invention, even in an area where azimuth blanking needs to be performed in order to prevent radio interference or the like, blanking of only a long pulse transmission signal enables short-distance coverage. And the air traffic control or monitoring function can be maintained in all directions.

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

FIG. 1 shows a radar apparatus according to one embodiment of the present invention.
In this radar apparatus, the gate circuit 14 is eliminated from the conventional apparatus so that the combined output of the combiner 3 is directly applied to the transmitter 4, and the signal stop control circuits 12a and 12b, and the azimuth blanking control circuit 13 Is provided.

The azimuth blanking control circuit 13 synchronizes with the antenna rotation angle signal and outputs an azimuth blanking control signal (second
(B) is generated and the same as the signal stop control circuit 12a.
Output to 2b separately. That is, when setting the azimuth blanking area in the predetermined azimuth range, the azimuth blanking control signal having the same content is output to both control circuits, or the azimuth blanking control signal is output only to the signal stop control circuit 12b. , Signal stop control circuit 12a
, A high-radar, unchanged signal is output.

As a result, in the above case, the signal stop control circuit 12a
And 12b perform the same control operation, and while the azimuth blanking control signal (FIG. 2 (b)) is at a low level,
The operation of the corresponding transmission signal generation system is stopped repeatedly. Therefore, the transmission signal supplied from the synthesizer 3 to the transmitter 4 has a short pulse transmission signal and a long pulse transmission signal in a portion corresponding to the azimuth blanking region, as shown in FIGS. Both are missing shapes. This is the same operation as the conventional one, and the radar coverage is as shown in FIGS. 2 (a) and (2).

On the other hand, in the above case, only the signal stop control circuit 12b controls the stop of the long pulse transmission signal generation system 2 and the stop control of the short pulse transmission signal generation system 1 is not performed. As shown in 1), a short pulse transmission signal exists within a period corresponding to the azimuth blanking region. As a result, the azimuth blanking area in the radar coverage area is formed only in the long-distance coverage area as shown in FIG. 2 (a) (1), and the detection function in the short-range coverage area is maintained without loss. Will be.

(Effect of the Invention) As described above, according to the radar apparatus of the present invention,
The short pulse transmission signal generation system and the long pulse transmission signal generation system can be controlled independently, that is, azimuth blanking is applied to both long and short pulse transmission signals or only to long pulse transmission signals. This makes it possible to adapt to the radio wave environment with respect to the surrounding area. In the latter case, in particular, there is an effect of preventing loss of radar detection characteristics in a short-distance coverage area.

As a result, even in an area where azimuth blanking must be applied due to radio interference, a short-distance coverage area can be secured by blanking only long-pulse transmission signals. There is an effect that the function can be maintained in all directions.

[Brief description of the drawings]

FIG. 1 is a block diagram showing the configuration of a radar apparatus according to an embodiment of the present invention, FIG. 2 is an explanatory diagram of the operation of the present invention, FIG. 3 is a block diagram showing the configuration of a conventional apparatus, and FIG. FIG. 5 is an explanatory diagram of an operation (when azimuth blanking is not applied), and FIG. 5 is an explanatory diagram of a conventional azimuth blanking method. DESCRIPTION OF SYMBOLS 1 ... short pulse transmission signal generation system, 2 ... long pulse transmission signal generation system, 3 ... synthesizer, 4 ... transmitter, 5 ... circulator, 6 ... antenna, 7 ... low noise amplifier, 8 ......
Switcher 9, short pulse receiving system, 10 long pulse receiving system, 11 synthesizer, 12 signal stop control circuit, 13 azimuth blanking control circuit, 14 gate circuit.

Claims (1)

(57) [Claims] 1. A long / short composite pulse type radar apparatus comprising a short pulse transmission signal generation system and a long pulse transmission signal generation system and transmitting a short pulse transmission signal before a long pulse transmission signal and transmitting the signal; A first control circuit for stopping the operation of the short pulse transmission signal generation system for a predetermined period in response to a control signal; and a second control circuit for stopping operation of the long pulse transmission signal generation system in a predetermined period in response to a second control signal. And an azimuth blanking control circuit for independently generating the first and second control signals in a predetermined azimuth range.