JPH04361185A - Wave receiver - Google Patents

Abstract

PURPOSE:To eliminate unnecessary signal and radar wave and the like unnecessary for monitoring without turning on and off the reception output signal using blanking signal. CONSTITUTION:A distributor 2 separates the RF signals received through an antenna 1 into two. A receiver 3 amplifies and detects the one of the RF signals separated by the distributor 2 and sends a reception output signal S1. A filter 4 receives the other RF signal separated by the distributor 2 and extracts only the frequency component in the radar pulse signal of the self-station. A receiver 5 amplifies and detects the output from the filter 4 and sends a reception output signal S2. A comparator 6 outputs the difference between the reception output signal S1 and the reception output signal S2 as an output signal S3.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radio wave receiving device, and more particularly to a radio wave receiving device that removes unnecessary signals (clutter) caused by radar waves in the same area and reflected waves from surrounding ground surfaces, buildings, etc.

0002

[Prior Art] Conventionally, this type of radio wave receiving device has a circuit that generates a blanking signal in response to a timing signal synchronized with the emission of a radar pulse signal, and a switch circuit that operates on and off in response to this blanking signal. By extracting the received signal through a switch circuit, the switch circuit is turned off and unnecessary signals are removed during transmission and while receiving reflected waves from the surrounding ground or buildings. It is being removed.

0003

[Problem to be Solved by the Invention] This conventional radio wave receiving device extracts the received signal by turning on and off the switch circuit according to the blanking signal, so it detects all received signals during the blanking signal period. I can't. Therefore, there is a problem in that important signals received during the blanking signal period, such as radio signals emitted by a moving object that suddenly appears or other radar pulse waves that suddenly start transmitting, cannot be detected. There is. Another problem is that the width of the blanking signal must be appropriately adjusted.

[0004] An object of the present invention is to provide a radio wave receiving device that removes unnecessary signals (clutter) and radar waves that do not require monitoring without turning on and off the received signal using a blanking signal.

[0005]

[Means for Solving the Problems] The radio wave receiving device of the present invention includes a distribution section that branches an RF signal received via an antenna into two, and amplifies and detects one of the RF signals branched by the distribution section. a first receiving section that sends out one received signal, a filter that receives the other RF signal branched by the distribution section and extracts only the frequency component of the radar pulse signal of the own station, and amplifies and detects the output of this filter. and a comparator section that outputs the difference between the first received signal and the second received signal.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be explained with reference to the drawings.

FIG. 1 is a block diagram showing one embodiment of the present invention. The RF signal received via the antenna 1 is split into two by the distribution section 2. One of the branched RF signals is supplied to the receiving section 3, where it is amplified and detected and output as a received signal S1. Further, the other branched RF signal is supplied to the filter section 4, where only the frequency component of the radar pulse signal of the own station is extracted, and then amplified and detected by the receiving section 5 and outputted as a received signal S2.

As shown in FIG. 2(b), the received signal S2 is a frequency component extracted by the filter section 4, that is, a frequency component that is reflected from the surrounding ground surface etc. following the radar pulse signal emitted by the local station. clutter, and the desired reflected radar pulse signal. Further, as shown in FIG. 2(a), the received signal S1 includes, in addition to the frequency component of the radar pulse signal of the own station, other signals having a high reception level.

[0009] Here, the comparator 6 compares the received signals S1 and S2.
By performing subtraction with , a signal S3 from which unnecessary signal components have been removed is output, as shown in FIG. 2(c). Therefore, since the signal S3 does not contain unnecessary signal components, it is an important signal with a frequency different from that of the own station's radar pulse signal.
For example, a radio signal from a moving object that suddenly appears nearby,
It is possible to detect other radar pulse signals that suddenly start transmitting. However, the reception level of the detectable signal must be higher than the reception level of the unnecessary signal component.

0010

As explained above, the present invention provides a filter that splits an RF signal received via an antenna into two, and extracts only the received output of one RF signal and the same frequency component as the own station's radar pulse signal. By taking the difference between the received output of the other RF signal that passed through the RF signal, unnecessary signal components reflected from the surrounding ground surface etc. can be removed.
Important signals with high reception levels that could not be detected during the blanking period can be detected.

[Brief explanation of drawings]

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

FIG. 2 is a waveform diagram showing an example of received output signals S1 to S3 shown in FIG.
(b) shows the output signal S2 of the receiving section 5, and (c) shows the output signal S3 of the comparing section 6, respectively.

[Explanation of symbols]

1 Antenna 2 Distribution section 3, 5 Receiving section 4 Filter 6 Comparison section S1 to S3 Reception output signal

Claims (1)

[Claims] 1. A distribution unit that branches an RF signal received via an antenna into two, and a first reception unit that amplifies and detects one of the RF signals branched by the distribution unit and sends out a first received signal. a filter that receives the other RF signal branched by the distribution section and extracts only the frequency component of the radar pulse signal of its own station; and a second filter that amplifies and detects the output of this filter and sends out a second received signal. A radio wave receiving device comprising: a receiving section; and a comparing section that outputs a difference between the first received signal and the second received signal.