Design of C-Band Microwave Oscillator

Previously, the implementation of Oscillators was realized using crystal oscillator followed by a chain of multipliers for good stability and phase noise. The new approach is to use a Dielectric Resonator Oscillator (DRO) or a Coaxial Resonator Oscillator (CRO). This approach provides very good long term stability, and better temperature performance. In this study a DRO with negative resistance amplifier circuit is realized. In this design, the DRO is created by coupling a dielectric resonator to a micros-trip line to create resonance effect. As a model for dielectric resonator, an RLC shunt circuit is employed. GaAs FET is used in as active circuit of the DRO that is installed in FR4 substrate. DRO circuit is designed and simulated using Keysight's Advanced Design system (ADS). According to simulation results, the Oscillation frequency of 7 to 8 GHz, Output waveforms and Phase noise exhibits a -125dbm at 100 KHz offset. +