2.4-GHz frequency synthesizer with open loop FSK modulator for WPAN applications

The design of a low cost, low power multifunction phase-locked loop (PLL) for homeRF application is presented. This PLL is used in reception mode, as frequency synthesizer and in a direct conversion transmitter as a frequency shift keying (FSK) modulator in the transmit mode. Experimental results showing the circuit performances are presented. All the circuits, including the loop filter capacitance, have been fully integrated on chip using 0.13 mum CMOS technology.direct conversion transmitterfrequency shift keying modulatorloop filter capacitance,CMOS technology.