Broadband radar radio frequency digital receiver based on microwave photons and signal acquisition and processing method

Abstract

The invention provides a broadband radar radio frequency digital receiver based on microwave photons and a signal acquisition and processing method. A mode-locked laser is used as an ultrashort pulselaser light source to generate optical pulses, and a tunable optical filter is utilized to divide frequency spectrum components of the optical pulses into a plurality of sub-bands so as to generate asub-pulse sequence; each sampling optical pulse group completes one-time sampling; a sampled optical pulse sequence is input to an electro-optical modulator and modulated by a radio frequency signal received by an antenna, so that the amplitude of the radio frequency signal is mapped to the intensity of the optical pulse; an optical signal after pulse width expansion is allocated to a signal conversion module through a wavelength division multiplexing module to be converted into a discrete time digital signal; and an information processing module reconstructs a complex signal according to thediscrete time digital signal and builds a one-dimensional image of a target. The broadband radar radio frequency digital receiver based on microwave photons does not require a frequency mixing link; and while ensuring the theoretical resolution of a broadband radar signal, a radar system is allowed to adopt more complicated waveforms, and can perform sampling at a sampling rate lower than a Nyquist sampling rate.

Description

technical field [0001] The invention belongs to the technical field of radar, and in particular relates to a microwave photon-based broadband radar radio frequency digital receiver and a signal collection and processing method. Background technique [0002] When the radar realizes the high-resolution detection function, it needs to adopt the broadband signal. For broadband signals, how to receive and reconstruct the signal is a big problem. The first challenge is the analog response of the receiver to large-bandwidth signals: to achieve centimeter-level resolution, even if the radar signal is modulated into a zero-IF signal through a frequency mixing link, its bandwidth is above GHz, which is difficult for traditional receivers to deal with Its effective response; followed by the requirements of the Nyquist sampling theorem, that is, the sampling rate must be at least twice the signal bandwidth to reconstruct the signal and process it. For large-bandwidth radar signals, thi...

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Problems solved by technology

However, in the currently disclosed technology, there is no method that can satisfy the above conditions at the same time

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