microwave system based on an internal modulation laser and a parallel Mach-Zehnder interferometer

Abstract

The invention discloses a method for generating microwaves based on an internal modulation laser and a parallel Mach-Zehnder interferometer. The method comprises a microwave module and a feedback control loop, Wherein the microwave module comprises a high-voltage amplifier, a lead zirconate titanate piezoelectric ceramic driver, an external semiconductor laser, an optical isolator, an optical switch, a first optical coupler, a second optical coupler, a first Mach-Zehnder interferometer, a fourth optical coupler, a first photoelectric detector, a high-pass filter and a spectrum analyzer; And the feedback control loop comprises a third optical coupler, a second Mach-Zehnder interferometer, a fifth optical coupler, a second photoelectric detector, an analog-to-digital converter and a field programmable gate array. The system is reasonable in design and low in instrument cost, and the output wavelength of the system can be adjusted within a wide frequency range.

Description

technical field [0001] The invention relates to a microwave system, more specifically to a microwave system based on an internally modulated laser and a parallel Mach-Zehnder interferometer, and belongs to the technical field of radio waves. Background technique [0002] With the continuous increase of people's demand for information, the current wireless spectrum resources are already very tight. Wireless communication systems must use higher frequency carriers for communication. Radio over fiber (RoF) technology is a technology that combines light and communication. It can provide broadband wireless access in the optical wireless network. Compared with ordinary electrical signals, it has the advantages of low power consumption, easy installation, wide bandwidth and avoiding interference. It has become one of the hotspots of international research in recent years. [0003] In order to improve the performance of the RoF system and reduce the cost, the generation of high-qual...

AI Technical Summary

Problems solved by technology

Among them, the external modulation method is the most widely used, but it also has obvious defects. The cost of the system is expensive, and the output frequency of the millimeter wave source limits the frequency range of the millimeter wave generated by the external modulation; The defect of changing the output wavelength of the laser causes only one frequency of millimeter waves to be generated; the defect of the optical phase-locked loop is that the line width of the laser is very strict, and a pilot needs to be inserted during transmission. In addition, the phase-locked channel and the data channel There is crosstalk, which will affect the receiver's recovery of the signal; the optical injection locking device is bulky, has high spuriousness, and poor stability

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