Compact duplexer using capacitive loaded dual mode resonator for GSM microcellular base station

This paper describes a compact dielectric resonator duplexer for GSM microcellular base station. A new size-reduced capacitive loaded TM dual mode resonator that consist of monoblock high K ceramics is proposed. The electrical performance of the duplexer is designed by using elliptic type equivalent circuit method. A 6 pole type duplexer at 900 MHz band is manufactured. It has low insertion loss of 1.1 dB, high attenuation of 58 dB. The volume is about 318 cc that is 1/3 of conventional cavity type.