A 3.8-5.5-GHz Multi-Band CMOS Frequency Synthesizer for WPAN/WLAN Applications

Abstract

In this paper, we present a 3.8-5.5 GHz multi-band CMOS frequency synthesizer for WLAN and UWB applications. In the multi-band frequency synthesizer, both new multi-mode prescaler and adaptive multi-band LC VCO are proposed. The proposed multi-mode prescaler produces six modes of divide-by-2/3, 4/5, 8/9, 16/17, 32/33, and 64/65. In the adaptive multi-band LC VCO, the gate width of cross-coupled MOS array is tuned to calibrate oscillation amplitude and alleviate 1/f flicker noise of MOS. The multi-band frequency synthesizer represents -121 dBc/Hz at 5 MHz offset from 5.24 GHz carrier. The multi-band frequency synthesizer consumes a total current of 26mA at 1.2 V, and is manufactured in 0.13-mum CMOS process technology