Concepts for RF Front-Ends for Multi-Mode, Multi-Band Cellular Phones

This paper describes front-end architectures of modern multi-mode, multi-band cellular phones and will discuss the requirements on RF filtering in such applications. Special focus will be on dual mode (GSM and WCDMA) cellular phones with four GSM and three WCDMA bands. On the one hand driven by forward integration - e.g., from PA function via transmit front-end to a fully integrated radio - on the other hand influenced by new requirements of 3G systems and the integration of complementary access, filtering components such as SAW and BAW filters have to solve several increased requirements simultaneously. New technologies are required to follow the demand of increased RF performance, reduced PCB area consumption and continuously decreasing component costs.