A novel tunable active duplexer MMIC

In this paper, an electronically tunable active duplexer suitable for reconfigurable wireless transceiver application is presented. For the first time, the design has been realized as a MMIC. A novel capacitance tuning circuit has been implemented in the active duplexer. The design and, simulation and measured results of the tunable active duplexer are presented. The active duplexer MMIC provides an electronically tunable isolation of 20 to 45 dB between isolated ports and a gain of 14.5 to 16.5 dB between coupled ports in the tunable range from 2.32 to 2.48 GHz in both transmit and receive modes. This chip is suitable for 2.3GHz WiMAX and WiBro applications.