Alexandre Reinhardt

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

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 Kt2 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.

Design of RF power divider/combiner based on surface acoustic wave technology

Power dividers/combiners are used as fundamental unit for power combining/splitting in different RF/Microwave circuits such as power amplifier modules, antenna array feeds or mixers. Most common types are based on quarter wave transmission line and their miniaturization is challenging especially in frequency less than GHz range where they exhibit very large physical size that make their use impractical or impossible in portable wireless devices. As an alternative, we propose to exploit the propagation of surface acoustic waves to implement RF signal splitting and combining functions, thus providing enhanced reduction of traditional power dividers/combiners for compact RF wireless architectures. SAW technology is well established and offer high level of miniaturization with high performance. This paper describes an innovative power divider/combiner based on parallel connected SAW coupled resonators filter (CRF).