A method for realizing microwave signal photonics frequency conversion and multi-channel phase shift by using a dual-polarization quadrature phase shift keying modulator

Abstract

The invention discloses a method for realizing photonic frequency conversion and multi-channel phase shift of a microwave signal by using a dual-polarization quadrature phase shift keying (DP-QPSK) modulator, relates to the technical field of microwaves and the technical field of optical communication, and can be mainly applied to beam forming, IQ demodulation and the like of the signal. As shownin an attached drawing, the scheme comprises a light source, a local oscillation source, an erbium-doped optical fiber amplifier, an optical splitter, a polarization controller, a polarizer and a photoelectric detector. According to the invention, the DP-QPSK modulator is used for carrying out modulation and polarization multiplexing on a radio frequency signal and a microwave local oscillator, after light amplification, power is divided into multiple paths, each path controls the amplitude and phase of an output signal through the polarization controller and the polarizer, and finally a phase-changed intermediate frequency signal is obtained through the photoelectric detector. According to the invention, the up-down frequency conversion and phase shift functions of signals can be realizedat the same time, the influence caused by periodic power fading is avoided, the system gain is large, and the system has the characteristics of simple structure, flexible tuning, large bandwidth, multiple functions and the like.

Description

technical field [0001] The invention relates to the fields of optical communication technology and microwave technology, and mainly realizes frequency conversion and multi-channel phase shifting of microwave signals through photonics technology. technical background [0002] As people's requirements for communication rates are getting higher and higher, electronic communication systems are now developing in the direction of high-frequency bands and large bandwidths. Traditional electronics-based signal processing technology has speed bottlenecks in electronic devices, large timing jitter, and serious electromagnetic interference. Photonics signal processing technology has a series of advantages such as simplicity, portability, wide bandwidth, and anti-electromagnetic interference, and has attracted much attention. [0003] Signal frequency conversion and phase shifting technologies are widely used in beamforming and other fields. At present, the transmitting end of electri...

AI Technical Summary

Problems solved by technology

But this structure has the following disadvantages: (1) When the frequency of the RF signal to be sent or received is high, due to the speed bottleneck of the electronic device, two stages of local oscillator frequency conversion are often required, and bandpass filtering is required for each stage of frequency conversion Filter out the up-converted or down-converted intermediate frequency signal for post-processing, the structure is complex, and there are many external interference factors

(2) The frequency range of the electric domain phase shifter limits the working frequency band of the system, and its frequency correlation limits the working bandwidth of the system

(3) When the signal bandwidth is very large, the analog-to-digital converter is required to have a higher sampling rate and operating frequency, and the current analog-to-digital conversion technology is difficult to meet

However, the existing solutions also have the following problems: (1) For the multi-channel frequency conversion and phase shifting technologies required for beamforming, the system complexity of many existing technical solutions will increase proportionally with the number of channels

(2) Most of the existing frequency conversion and phase shifting technologies only realize the down conversion of the signal, so the solution is only applicable to the receiving and processing of the signal

(3) In a few schemes that can realize up-down conversion and phase shifting, the problem of periodic power fading caused by optical fiber transmission to the signal has not been solved

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