Front-End Scalability for Multi-Band Multi-Mode Radios
The worldwide expansion of new frequency bands and standards for mobile telecommunications has exposed a problem with the existing scalability model for RF Front Ends. Many current mobiles support single WCDMA bands and utilize discrete WCDMA PA adn DPX, or a PA-DPX Modulte. The implications to the RF Front End are relatively incremental increases in size and cost. A limited number of mobiles support 2 or even 3 WCDMA bands, and in these applications the added size adn cost scales linearly with the number of bands supported. The trend for future mobiles is toward further increase in WCDMA bands and stadards to support increased data throughput and locational transparency. Scaing to 4 or 5 WCDMA bands becomes a size and cost burden on Front End designers. Further expansion of data-centric mobiles into LTE, with complex MIMO adn Coexistence implications, creates a potentially untenable situation for designers that are simultaneously being required to reduce mobile from factors and extend battery life.