Characterizing and Validating RFFE and SPI Bus Performance
应用文章
RF power amplifiers (PAs) and front end modules (FEMs) are essential for modern wireless device operation. PA and FEM components, including PAs, LNAs, tuners, filters and switches, typically include a serial bus interface to support reconfigurations for power and band settings. As the variety of RF protocols increases so do the demands on the PA/FEM components and RFIC to PA/FEM communications. To better address these serial communications, the MIPI® alliance has developed the RF front end interface (RFFE) specification. The MIPI RFFE communications bus standard provides both PA/FEM suppliers and users a common serial communications framework to build on.
Validating RFFE communication robustness for new PA/FEM components includes basic communication validation for PA/FEM control, as well as extensive bus timing and logic level margin testing. Methods to characterize and validate PA/FEM serial bus performance and IO pin parametric performance are described in this application note. RFFE interface test is the primary focus, although the general concepts apply to other master/slave serial bus configurations including SPI.