The RF Front End (RFFE) control interface is defined to offer a common Interface for controlling RF front-end devices. Most commonly used Front-End devices include Power Amplifier, Low-Noise Amplifiers, Filters, Switches, Power Management Modules, and Antenna Sensors etc. These Functions can be residing in the same chip or in a separate chip.
Mobile Radio communications is trending towards complex multi-radio systems comprising of several transceivers. The RFFE bus is usable in such configurations by supporting single one Master and one Slave configuration to Multi-Master with many slaves. It is designed to support existing 3GPP standards such as LTE, UMTS, HSPA, EGPRS.
RFFE is a 2 wire serial interface and utilizes a relatively high bus frequency of 26MHz and Timing accurate trigger mechanisms to allow control of timing critical functions.