Reconfigurable RF circuits for future multi-mode multi-band mobile terminals

Reconfigurable radio frequency (RF) circuits will be a predominant solution for future global and compact mobile terminals, which supports 2G, 3G, and LTE cellular systems in various frequency bands. A single-path configuration and use of single-band devices with distributed reconfigurable matching networks have the potential to achieve the optimum RF frontend for future multi-band mobile terminals. Considering the difficulties in configuring a practical tunable band-pass filter as a top filter or duplexer, collaboration between the filter and lownoise amplifier (LNA) is a candidate to achieve the performance level required for the RF front-end. In addition, a power amplifier (PA) is also one of the key components in the RF frontend because its power consumption affects operating time of the terminal. This paper overviews the recent progress in our research on the reconfigurable LNA and PA. These RF circuits will contribute to the multi-mode band-free operation in future mobile terminals.