Mode hopping suppression method and system for optoelectronic oscillator

Abstract

The invention discloses a mode hopping suppression method and system for an opto-electronic oscillator. The method comprises steps: a phase frequency detector compares an output signal of a low frequency reference oscillator with a signal of a double-loop structure point frequency opto-electronic oscillator through frequency division of a frequency divider, and if the frequency difference betweenthe two exceeds the maximum traction range of a phase locked loop, a frequency control loop is triggered to start working; a frequency control loop generates a control signal and sends the control signal to a voltage-controlled radio frequency phase shifter in a short loop of the double-loop structure point frequency opto-electronic oscillator, the oscillation frequency of the double-loop structure point frequency opto-electronic oscillator is tuned until the frequency difference of output signals between the low frequency reference oscillator and the frequency divider falls in the traction frequency range of the phase locked loop, the frequency control loop is triggered to stop working. Mode hopping and frequency drift suppression on the double-loop structure point frequency opto-electronic oscillator can be realized based on one frequency control loop and the phase locked loop, and long-term stability of the oscillation frequency is achieved.

Description

technical field [0001] The invention relates to a mode hopping suppression method and system suitable for a photoelectric oscillator. The system uses a frequency control loop and a phase-locked loop to realize the phase locking between the photoelectric oscillator and the reference oscillator, which overcomes the mode hopping caused by the photoelectric oscillation loop due to environmental temperature, vibration and other factors, and belongs to the field of microwave photonics. Background technique [0002] The optoelectronic oscillator is a new type of microwave oscillator capable of generating high-frequency microwave and millimeter-wave signals. It has the characteristics of extremely low phase noise, phase noise is almost independent of frequency, and frequency broadband can be tuned. It has important application value in many fields such as high-performance radar systems, broadband wireless communication systems, broadband test systems, and deep space exploration. In...

AI Technical Summary

Problems solved by technology

However, due to the change of the optical fiber in the optoelectronic oscillator with the temperature, the frequency of the cavity mode changes, which will eventually cause the phase-locked loop to lose lock, thereby causing mode hopping.

Images