A novel distributed voltage-controlled oscillator for wireless systems

A novel distributed voltage-controlled oscillator based on distributed amplifier topology is presented in this paper. The distributed voltage-controlled oscillator architecture proposed here is new. The oscillator tuning is achieved by changing the center frequency of a narrowband varactor tunable band-pass filter in the feedback loop. The measured tuning range of the prototype oscillator is 1.7 GHz (from .7 to 2.4 GHz). The highest measured harmonic level is 19 dB below the fundamental. The oscillator phase noise over the tuning range is approximately -116 dBc/Hz at 1 MHz offset as revealed by simulations. The design as well as simulation and measured results of the oscillator are summarized. The oscillator topology is suitable for monolithic implementation.