Monolithic 1-Chip FBAR duplexer for W-CDMA handsets

Film bulk acoustic resonator (FBAR) filters and duplexers are receiving increasing attentions in RF systems due to the advantages of having high power handling capability, high Q-factors, good thermal stability, require a small volume and are relatively cheap. There are currently no published papers and research about FBAR 1-Chip duplexer, which have been designed with Tx and Rx filters because it is a very challenging task. We report for the first time that a monolithic 1-Chip RF duplexer is achieved with the size of 2.5 mm × 2.5 mm using thin FBAR technology to meet the stringent demand for miniaturization and monolithic integration of duplexers in RF communication systems. In this work, a novel 1-Chip duplexer is designed by EM (electromagnetic) simulation and RF circuit simulation using HFSS and ADS. The highest insertion losses in the pass band (1920–1980, 2110–2170 MHz) are measured below 4.35 dB, and attenuation are over 39 dB.