BAW/SAW/IPD hybrid type duplexer with Rx balanced output for WCDMA Band I

This paper describes a 3.0 ° 2.5 ° 0.7 mm
³
wideband code division multiple access (WCDMA) Band I duplexer with receiver (Rx) balanced output we developed. The low-loss and power-durable film bulk acoustic resonator (FBAR) and the single-to-balanced double mode SAW (DMS) were utilized for the transmitter (Tx) and the Rx filter respectively. It was experimentally confirmed that the 2
^nd
distortion of FBAR was significantly worse than that of the surface acoustic wave (SAW). In order to suppress the 2
^nd
harmonic due to the nonlinear distortion of the duplexer and the power amplifier (PA), a notch circuit was implemented at the antenna port using our high-Q Integrated Passive Devices (IPD) technology. As a result, we realized the duplexer with suppressed nonlinear distortion as well as excellent filter response.