Software simulation accurately predicts the microwave oscillator Q factors

Prediction of the oscillator Q factors, prior to its fabrication, is often necessary in determining the oscillator's operating parameters such as; phase noise, pulling figure, tuning bandwidth and frequency stability. This paper first discusses the techniques used for the Q factor measurement and then utilizes the HP EEsof Series IV design software to measure the Q factors associated with the microwave resonators and oscillators. It also compares the results of the software simulation with the actual measurements of the Q factors. The measured data indicates that, if the oscillator elements are accurately modeled, the software measurements are very close to the actual hardware measurements.