Four-wave mixing based continuously trap wave tunable microwave photonic filter

Abstract

The invention discloses a four-wave mixing based continuously trap wave tunable microwave photonic notch filter. Multi-wavelength laser is generated by four-waving mixing to serve as a light source of the microwave photonic filter to realize a multi-tapping effect. Sidebands and phases of photoelectric current generated after phase modulation control by a waveshaper form trap waves, and phase shift magnitude is introduced additionally to form a complex coefficient to realize continuous tuning of the trap waves. Passband center frequency of output radio-frequency signals of the microwave photonic filter has characteristics of tunable band-reject filter waves, and tunability in trap wave center frequency of the filter is realized according to the phase shift magnitude introduced to optical carriers and modulating signals by the waveshaper. The microwave photonic notch filter has advantages of simple structure, developed operation techniques and low cost, solves problems of small tuning range and failure in continuous tunability of existing phase modulation based microwave photonic notch filters and is applicable to fields of national defense, industrial production and civilian use.

Description

technical field [0001] The invention belongs to the technical field of microwave photon filtering, and in particular relates to a microwave photon filter which introduces a phase shift amount to realize tunable notch center frequency. Background technique [0002] Microwave photonic filter is an important branch of microwave photonics. It modulates the input radio frequency (RF) signal to the optical signal through the modulator, processes the RF signal in the optical domain, and finally outputs the filtered microwave through the optical receiver. Signal. Using this method has the advantages of low loss, high bandwidth, immunity to electromagnetic interference, light weight, and high sampling frequency. These significant advantages make microwave photonic filtering systems a hot technology in broadband radio frequency signal processing and attract international attention. In recent years, researchers have conducted in-depth research on it, and have obtained many experimenta...

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Problems solved by technology

[0004] The purpose of the present invention is to solve the problem that the existing microwave photon filter has a small tunable range and cannot be continuously adjusted, and provides a tunable notch microwave photon filter with simple structure and mature manufacturing technology. The four-wave mixing effect produces multi-wavelength laser as the light source of the microwave photon filter to realize multi-tap; the phase and sidebands of the photocurrent generated after phase modulation are controlled by the wave shaper (Waveshaper) to form filling waves, and additionally introduce phase shift Quantities form complex coefficients to realize continuous tuning of the notch, and finally can realize the tunable center frequency of the passband of the notch filter

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