A robust CMOS Bluetooth radio/modem system-on-chip

The relaxed constraints on Bluetooth RF front-end implementation, together with the requirement of frequency hopping, result in a frequency offset and drift elimination or reduction problem. In the Spirea Bluetooth radio solution BlueTraC, a scalable digital demodulator is used, which gives a flexible, fast, and tunable frequency adjusting implementation. To increase the dynamic range the existing transmit chain is used to tune the LO during receive mode.