Nonlinear analysis and optimization of a Distributed Voltage Controlled Oscillator for Cognitive Radio

Nonlinear design and optimization of a Distributed Voltage Controlled Oscillator (DVCO) suitable for Cognitive Radio is presented. Harmonic Balance (HB) based optimization techniques have been used to obtain an optimized design of the DVCO aiming at minimizing the output power variation along the frequency band. A prototype has been built showing good agreement with simulation. The measured DVCO has a frequency tuning range from 0.75 GHz to 1.85 GHz, an average dissipation of 59 mW, and an average output power of 5.2 dBm. The average measured phase noise at 1 MHz offset from the carrier across the tuning range is -111.2 dBc/Hz.