Microwave photon radar

Abstract

The invention discloses a microwave photon radar. The microwave photon radar comprises a radar signal generation module which is used for generating a narrow-band radar signal, converting the narrow-band radar signal into two paths of optical signals and outputting the two paths of optical signals. And the radar signal transmitting module is used for receiving one optical signal, converting the optical signal into a radio frequency antenna signal and transmitting the radio frequency antenna signal. And the reference signal delay module is used for receiving the other path of optical signal and carrying out delay processing to obtain a reference signal. And the receiving frequency mixing module is used for receiving the reference signal and the echo signal and carrying out dechirping frequency mixing receiving to obtain a dot frequency signal. And the analysis processing module is used for receiving, processing and analyzing the dot frequency signals. By means of multiple cycles of optical signals, interval-free and repetition-free multiplied delay is automatically achieved, an optical switch can be adopted in the delay to switch different delay amounts participating in the cycles, and therefore the length of an optical fiber ring is controlled, the cycle period can be set, and the function of the optical switch is replaced. On the basis of the adjustable and controllable optical delay line, the microwave photon radar can realize non-blind area and non-repeated detection and mapping in the maximum range.

Description

technical field [0001] The invention belongs to the technical field of radar, in particular to a microwave photonic radar. Background technique [0002] Microwave photonic radar uses optical technology to generate ultra-wideband radar signals with high resolution and anti-clutter functions. In order to process ultra-wideband radar signals, the method of de-slope mixing is often used, which can effectively reduce the frequency of receiving and processing intermediate frequency signals and reduce the pressure of back-end processing of analog-to-digital conversion. [0003] The main factors that determine the frequency of the IF signal received by the de-skew mixing method are the bandwidth of the radar signal, the pulse duration, and the time difference between the echo and the transmitted signal. [0004] [0005] Although the radar signal bandwidth B is adjustable, it should not be adjusted to a smaller value to lose the technical advantages of microwave photonic radar u...

AI Technical Summary

Problems solved by technology

However, there are several problems in this method: 1. The multi-channel delay structure is complex, and each delay line needs a modulator and a photoelectric converter. The basic idea is still limited to the fixed delay line structure, but it is combined in parallel. 2. The The delay structure does not solve the problem that the reference signal is continuous without interval and without repetition, because the multi-stage delay line is a parallel delay structure, the delay amount of the delay line is fixed, and each set of delay lines corresponds to a fixed range, which may not form a detection blind zone with the original radar detection range , 3. This method needs to split the reference signal, which increases the additional insertion loss. 4. This method needs to split the echo signal, which also increases the additional insertion loss.

In addition, the automatic optical cycle time delay structure mentioned in the prior art, but this structure only has the automatic cycle function, does not have the controllable and adjustable function, which seriously limits the wide application of the incremental delay structure and lacks practicability

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