A 1V 220MHz-Tuning-Range 2.2GHz VCO Using a BAW Resonator

Abstract

The frequency stability of integrated oscillators has become an increasingly important issue for the next generation of digital RF transceivers. RF oscillators using high-Q BAW resonators have been demonstrated to provide excellent performance in terms of stability, phase noise and power consumption. Nevertheless, the frequency tuning range of BAW oscillators is still limited by the piezoelectric coupling coefficient Kt <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> of the piezoelectric material which defines the frequency shift between the resonance (series) and anti-resonance (shunt) frequencies of the resonator. The maximum tuning range for such a voltage-controlled oscillator will never exceed this frequency shift.