In the first part of this thesis, RF specifications of the CSR Bluetooth module were tested rigorously by means of proper equipment setup and manipulation. The tested parameters in the transmitter include output power, spectrum and modulation characteristics. The tested parameters in the receiver include sensitivity and received signal strength indicator. The second part of this thesis was mainly focused on some mixed-signal integrated-circuit designs that can be generally applied to the Bluetooth RF front-end. The design examples include the phase frequency detector, charge pump, and frequency divider in the applications of phase-locked loop. A transconductance-capacitor low-pass filter with tunable cut-off frequencies was also designed to suppress the spurious signals from RF front-end into baseband.