Study Of High Stability K-band Push-push Oscillator

Oscillator is one of the core components of wireless communication,radar,navigation and other systems,and its performance directly affects the parameters of the entire system.As the performance requirements of modern communication,radar and other systems for the phase noise and stability of microwave oscillators continue to increase,and the development requirements for miniaturization and integration.Under this background,a high-stability push-push oscillator using an open-loop resonator structure is proposed in this thesis.The main work of the thesis is as follows:Firstly,this article briefly introduces the principle of the oscillator and analyzes the equivalent circuit model of the oscillator,studies the three methods of discriminating the working state of the oscillator,and explains the definition and model of phase noise parameters.The coupling mode and characteristics of dielectric resonator,microstrip line and varactor diode are analyzed.Secondly,a push-recommendation oscillator is designed and implemented.In this structure,the addition of the variable-capacitance diode module can effectively reduce the impact of the inconsistency of active devices on the oscillator circuit,reduce the interference of the two suboscillators on the output signal at the base frequency,and enable the oscillator to obtain an output signal frequency adjustable range of about 200 MHz.The test results show that when the output signal frequency is 20.96 GHz,the output power is approximately-4.59 d Bm,the phase noise reaches-66.50 d Bc/Hz at 10 KHz,and-94.31 d Bc/Hz at 100 KHz,and the fundamental wave rejection reaches-25.42 d Bc.Finally,in view of the shortcomings of traditional dielectric oscillators such as poor consistency and large debugging workload,as well as the requirements for miniaturization and integration,a push-push oscillator structure based on microstrip open-loop resonator is proposed in this thesis.The microstrip resonator is a double-mode open-loop resonator.The open-loop structure can effectively reduce the overall size of the circuit,and the resonant frequency of the odd and even mode resonators can be adjusted to work in the same frequency band,so as to improve the frequency selectivity of the resonator.The test results show that the operating frequency of the oscillator is 21.04 GHz,the output power is approximately-10.35 d Bm,the phase noise is-63.40 d Bc/Hz @10 KHz,-85.62 d Bc/Hz @100 KHz,and the harmonic suppression is-18.03 d Bc.This thesis compares and analyzes the test results of the two oscillators,proposes improvements to the design deficiencies,and verifies the rationality and feasibility of the proposed open-loop resonator push-push oscillator structure design.Complete the miniaturization and integrated design of microwave oscillators.