Research On Push-Push Millimeter Wave Point Frequency Source With Ultra Low Phase Noise And Low Spur

Millimeter wave is widely used in wireless communication,radar detection and other aspects by virtue of its high frequency,wide bandwidth and low delay.With the development of relevant electronic information systems,higher requirements have been put forward for the phase noise and stray of millimeter wave sources,so as to adapt to large capacity low bit error rate transmission and high sensitivity detection.Based on the topology of oscillators,this thesis analyzes the oscillator phase noise optimization according to the Lesson equation and then summarizes some useful measures to optimize phase noise,among which the coupled oscillator can reduce phase noise significantly and is widely used in the design of low phase noise oscillators.In this thesis,the mechanism of phase noise reduction of coupled oscillator is analyzed theoretically,and finally considering the reliability and comprehensive performance,the push-push oscillator,a working mode of the coupled oscillator,and dielectric oscillator are selected for the design of a millimeter wave source with low phase noise and Low spurious.In this thesis,a new push-push oscillator scheme is carried out on the basis of the existing push-push oscillator scheme,which is designed by using duplexer and phase shifter.The new scheme can reduce the output spurious,and realize the circuit phase balance,which is beneficial to optimize the phase noise.Using the new scheme,a 35 GHz Push-Push millimeter wave dielectric oscillator with an output phase noise of-130 d Bc/Hz@1 MHz is designed.The phase noise optimization of the coupled oscillator is verified by comparing it with the single-channel oscillator.Based on the push-push dielectric oscillator,a sampling phase-locked loop is designed with a crystal oscillator with very low phase noise as a reference.By adjusting the loop bandwidth,the optimal output of phase noise is achieved.Finally,a push-push millimeter waves point frequency source with ultra-low phase noise and low spurious is obtained.The phase noise of this source is-119 d Bc@100 k Hz,-127 d Bc@1 MHz,and the spurious suppression is less than-70 d Bc.