Photon method and system for realizing microwave down-conversion and phase shift by using integrated devices

Abstract

The invention provides a photon method and system for realizing microwave down-conversion and phase shift by using integrated devices, and belongs to the field of microwave photonics. Firstly, opticalcarriers generated by a laser are input to a double-parallel Mach-Zehnder modulator after passing through a polarization controller, a radio frequency signal is modulated by an upper arm sub-modulator, and carrier suppression double-sideband modulation is realized by DC bias; a local oscillator signal is modulated by a lower arm sub-modulator, and the carrier suppression double-sideband modulation is realized by the DC bias; the DC bias of a main intensity modulator is used for changing the phase difference between the radio frequency optical signal and the local oscillator optical signal. A-1 order optical sideband is filtered from an output carrier suppression double-sideband modulation optical signal by an optical bandpass filter, a +1 order optical sideband is retained, and the useless optical sideband is suppressed below the noise floor. Then, power amplification is performed on the optical signal to compensate the insertion loss of modulator and the filter. At last, a down-conversion signal subjected to phase shift is obtained by performing beat frequency by using a photodetector. A very pure frequency spectrum signal is output, and the performance of an integrated functionlink of down-conversion and phase shift is improved.

Description

technical field [0001] The invention proposes a photon method and system for realizing microwave down-conversion and phase shifting by utilizing an integrated device, and the method and system belong to the field of microwave photonics. Background technique [0002] Traditional microwave communication can be launched in any direction and is easy to build and reconfigure, but limited by the transmission performance of coaxial cables, microwave communication has shortcomings such as small bandwidth, high loss, severe electromagnetic interference, and bulky size. Optical fiber communication can solve the above problems well, and has the advantages of low loss, anti-electromagnetic interference, and ultra-large bandwidth. As an emerging interdisciplinary subject, microwave photonics combines optical fiber technology with microwave communication to form a new type of communication link. The microwave photonic link adds electrical / optical and optical / electrical conversion, modula...

AI Technical Summary

Problems solved by technology

However, the only DC bias of the dual-drive Mach-Zehnder modulator in this link is used to achieve phase-shifting operation, so carrier suppression cannot be achieved, resulting in the output spectrum of the dual-drive Mach-Zehnder modulator containing the carrier and higher order Spurious signals such as sidebands, even if fiber Bragg grating filters are used, unwanted spurious signals still exist

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