A 6.6 GHZ Quadrature Frequency Synthesizer With -78 DBC Reference Spur for Uwb Application

Abstract

Abstract-An integer-N quadrature frequency synthesizer for single-band UWB application was designed in 0.18 µm CMOS technology. A modified bottom-series quadrature voltage-controlled oscillator (QVCO) based on reconfigurable LC tank is employed to provide quadrature signals and cover a range from 6.48 GHz to 7.07 GHz. In order to suppress the reference spur levels, an improved charge-averaging charge pump and a highly linear phase-frequency detector (PFD) are used. From the carrier of 6.6 GHz, the measured reference spur is −78.2 dBc, and the measured phase noise is −115.4 dBc/Hz at 1 MHz offset. The frequency synthesizer including buffers consumes a total power of 99 mW from a 1.8 V power supply. Chip size is 1.6 mm × 0.9 mm.