Circuit co-simulation and measurement techniques applied to voltage-controlled oscillator design

A voltage-controlled oscillator (VCO) was designed for operation in C-band for use in a microwave point-to-point radio system. Microstrip technology was chosen for resonator implementation since it offers ease of manufacturing and frequency adjustment. The design was performed using an electromagnetic harmonic balance co-design technique in conjunction with linear analysis in order to achieve first pass success. Emphasis in this work is the ability to use multiple design approaches and test techniques while validating in advance with co-simulation. The measured frequency against tune voltage data shows excellent agreement with simulation. Maximum deviation of 2% between the two was observed. The VCO tuned from 4.3 to 5.4 GHz as the tuning voltage was varied from 0 to 9 V representing a tuning bandwidth in excess of 20%. Power dissipation is 150 mW. Phase noise over the tune range was better than -108 dBc/Hz at 100 kHz offset. The oscillator design efficiency, applicable to wider tune range designs, is greater than 2%. The hybrid oscillator figure-of-merit functions evaluated in this work exceeded comparable silicon-integrated implementations.