Frequency Synthesizer and FSK Modulator for IEEE 802.15.4 Based Applications

The feasibility of a low cost, 2.5 Volts supply phase-locked loop for HomeRF application is demonstrated. Based on IEEE 802.15.4 specifications, this low power and low cost, multi-function PLL is used both in a single conversion receiver as frequency synthesizer and in a direct conversion transmitter as a frequency shift keying (FSK) modulator. Measurement results of the PLL and the open loop modulator together with VCO performances are presented. All the circuits have been fully integrated using 0.28μm CMOS technology.