Microwave power detection using ferroelectric thin film varactors

摘要

Ferroelectric, barium strontium titanate thin film varactors have been used to rectify and detect microwave signals with frequencies ranging from 2GHz to 3GHz. Anharmonic dipolar resonant frequencies from these thin fims were shown to have strong dependence on film thickness with some amount of voltage-controlled tunability. Experiments were performed using lock-in detection of a 100% amplitude modulated microwave signal with varying power levels. An on-resonant sensitivity of 0.6mV/mW was observed. Power detection sensitivity was shown to have built-in bandpass filtering resulting from resonant line shape.