A compact 802.11 a/b/g/n WLAN Front-End Module using passives embedded in a flip-chip BGA organic package substrate

This paper discusses the design and implementation of a compact RF front-end-module for 802.11 a/b/g/n application. A high performance embedded passives technology has been developed by extending existing multilayer FCBGA packaging substrate technology to include thin film capacitors, resistors and spiral inductors. Using these basic elements, all of the passive building blocks for the RF front-end module (FEM) have been designed and characterized individually. Several of these building blocks have then been used in combination with surface mounted active dies to realize a dual-band one-transmit/one-receive WiFi FEM with dimensions of 8 mm times 8 mm times 1 mm. Preliminary measurements indicate small signal gain of 10 dB at 2.4 GHz for the Rx chain.