Efficient BAW Filtering Solution for EDGE Transmitter

This paper presents a bandpass filter for DCS/EDGE transmitter using bulk acoustic wave technology. It is designed to filter PA´s harmonic frequencies and out-of-band noise generated by sigma-delta modulator in DCS/EDGE architecture. The filter is based on solidly mounted resonators electrically coupled in a ladder type topology; it achieves 2.4 dB insertion loss including matching network to 50 Omega, more than 15 dB of return loss over the 75MHz DCS band. Linearity and power handling capability characterizations are detailed. This filter is combined with a power amplifier using STMicroelectronics´ 0.25 mum BiCMOS technology, it is a first step to develop a power amplifier module for GSM/EDGE standard in the DCS frequency band