This paper presents a 55nm 4-in-1 (11b/g/n, BT, FM, and GPS) radio assembled side-by-side with a 3-metal layer integrated-passive-device (IPD) chip in a QFN40 package. One 2.4GHz transceiver is area-efficiently shared between WiFi and Bluetooth systems. Including a 3dB IPD insertion loss, at chip output (antenna port) the saturated output power of the 11bgn integrated PA is 25dBm; the receiver noise figure is 6dB and 7dB in WiFi and BT modes, respectively. The shared synthesizer locks to within 4ppm target frequency during WiFi/BT channel switching in less than 23 usec. Tracking sensitivity of the GPS receiver and the sensitivity of the FM receiver (including IPD loss) are -162dBm and 2.7dBuVrms, respectively. The IPD chip contains a 2.4GHz WiFi/BT balanced tri-section filter and matching network; a 2.4GHz/1.6GHz diplexer; and a GPS 5th order elliptical filter and its matching network. The radio and IPD die sizes are 3.4mm 2 and 3.1mm 2 , respectively.

In recent years, the increasing popularity of mobile devices, such as smart- phones and tablets, is driving the demand for integrating multiple radios on a single SoC to reduce cost, form factor and external BOM. These devices require ubiquitous wireless connectivity, which means concurrent operation with different radios. While concurrent operation of multiple radios brings excellent user experiences, there exist great challenges in dealing with radio co-existence in an SoC. For example, concurrent operation between WiFi and BT, both oper- ating in the 2.4GHz ISM band, sets additional requirements in RF front-end cir- cuits and system control. In addition, thermal effect of the integrated WiFi PA needs to be compensated to minimize its impact on the frequency-precise GPS system.