5-GHz Frequency Synthesizer With Auto-Calibration Loop

Abstract

A 5-GHz frequency synthesizer for ZIGBEE(IEEE 802.15.4) was implemented. It consumes 13.5 mW adopting CMOS Logic divider and robust VCO from process and temperature variation by body voltage control of current source. It incorporates an automatic capacitor-bank tuning loop to extend frequency tuning range. This synthesizer was fabricated in 0.18-um technology; it consumes 7.5 mA at 1.8 V and offers 100 kHz-loop bandwidth and always -103 dBc/Hz at an offset of 1 MHz. the lock time is 30 us. The PLL output tuning range is 14% from 2.258 GHz to 2.614 GHz.