Based On The Small Step Of Drvco Low Phase Noise Frequency Source Design

In modern microwave communication system, low phase noise frequency source plays a very important role, especially in the field of military and national defense, such a key role becomes even more evident. Because of its excellent noise performance, purity and stability of the spectrum, voltage-controlled dielectric resonator oscillator (DRVCO) is widely used in frequency synthesis and microwave oscillation source.This thesis puts forward a strategy in detail about how to realize the X-band low phase noise frequency source using DRVCO with small step.Firstly this paper introduced the two basic models of oscillator to discuss the the linear model of phase noise. From the coupled model of the dielectric resonator (DR), Bandstop-type DRO theories and models was discussed. ADS was uesd for circuit design simulation, and a reflective DRVCO was designed. Through the measurement, the test results were in good agreement with the simulation results, the main design goal was reached.Then this paper introduced the principles and characteristics of DDS to discuss its output signal spurious. Part of measures to reduce the spurious response was summed. At the same time, this article also alsoanalyzed PLL circuits, discussed the phase noise index of phase-locked loop. Through the well design of each parameter, the X-band low phase noise signal source based on DRVCO and DDS+PLL with small step is realized successfully.Finally, the system test results were analyzed, and the inadequacies and a follow-up improvement measures were pointed out.