Title :
Multi-mode RF front-end circuit
Author :
Kawai, Kunihiro ; Okazaki, Hiroshi ; Narahashi, Shoichi
Author_Institution :
Res. Labs., NTT DOCOMO, Inc., Yokosuka, Japan
Abstract :
This paper proposes a novel RF front-end circuit for multi-mode/multi-band mobile communication terminals. The RF front-end circuit functions as both a tunable duplexer for a frequency division duplex system and a single-pole double-throw (SPDT) switch with a tunable bandpass filter for a time division duplex system. The circuit comprises two pairs of transmission lines, switches, and variable reactance circuits. The proposed circuit can change transmission and reception frequencies when it functions as a duplexer. The circuit can also tune the center frequency and bandwidth independently when it functions as the SPDT switch with a bandpass filter. This paper shows the characteristics of the proposed circuit at 2.5 GHz, 3.5 GHz, and 4.5 GHz. The results confirm the dual operation of the proposed circuit.
Keywords :
band-pass filters; frequency division multiplexing; microwave switches; mobile communication; radiofrequency integrated circuits; transmission lines; frequency 2.5 GHz; frequency 3.5 GHz; frequency 4.5 GHz; frequency division duplex; multiband mobile communication terminals; multimode RF front-end circuit; multimode mobile communication terminals; single-pole double-throw switch; time division duplex system; transmission lines; tunable bandpass filter; tunable duplexer; variable reactance circuits; Band pass filters; Microwave filters; Power transmission lines; Radio frequency; Switches; Switching circuits; Wires;
Conference_Titel :
Microwave Conference (EuMC), 2011 41st European
Conference_Location :
Manchester
Print_ISBN :
978-1-61284-235-6