Spurious-free dynamic range improving method based on single sideband modulation

Abstract

The invention relates to a spurious-free dynamic range improvement method based on single sideband modulation. The spurious-free dynamic range improvement method comprises the following steps that: step 1, a laser device emits an optical carrier S1; step 2, a radio frequency input signal S2 modulates an optical signal S1 output by a laser through using a phase modulator so as to obtain and outputa phase modulation signal S3; step 3, the phase modulation signal S3 passes through a third-order intermodulation distortion suppressor, and then a single-sideband phase modulation signal S4 with a certain carrier-to-sideband ratio is output; and step 4, a photoelectric detector demodulates the signal S4 to suppress third-order intermodulation distortion in a output radio frequency signal S5, andan output signal of the photoelectric detector is input into a frequency spectrograph to be analyzed. The third-order intermodulation distortion suppressor obtains the single-sideband signal with a certain ratio of an optical carrier to +2-order sideband amplitude after carrying out amplitude-frequency processing on the signal, and the signal is extracted by the photoelectric detector in the step4, so that a spurious-free dynamic range of a spurious-free dynamic range link is improved.

Description

technical field [0001] The invention relates to the field of optical communication and the technical field of microwave photons, in particular to a method for improving the spurious-free dynamic range based on single-sideband modulation. Background technique [0002] Microwave photonics technology, MWP, Microwave Photonics, uses optical technology to transmit, process and apply microwave signals, combining the advantages of microwave technology fineness and photon technology broadband, in satellite communications, radio and television, optically controlled phased array antennas and navigation, etc. It has been widely used in many military and civilian fields. Radio-over-fiber system, ROF: radio-over-fiber, is one of the important applications of microwave photonic technology, usually composed of central office, optical fiber link and remote antenna unit. ROF modulates radio frequency signals onto optical signals and transmits them through optical fibers, and finally demodul...

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Problems solved by technology

[0005] For this reason, the present invention provides a method for improving spurious-free dynamic range based on single-sideband modulation, in order to overcome the IMD3 suppression problem in the ROF link in the prior art and avoid the periodic power caused during long-distance transmission Attenuation problem

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