A 6-9 GHz 5-band CMOS synthesizer for MB-OFDM UWB

An ultra-wideband frequency synthesizer is designed to generate carrier frequencies for 5 bands distributed from 6 to 9 GHz with less than 3 ns switching time.It incorporates two phase-locked loops and one single-sideband （SSB） mixer.A 2-to-1 multiplexer with high linearity is proposed.A modified wideband SSB mixer,quadrature VCO, and layout techniques are also employed.The synthesizer is fabricated in a 0.18μm CMOS process and operates at 1.5-1.8 V while consuming 40 mA current.The measured phase noise is -128 dBc/Hz at 10 MHz offset,and the sideband rejection is -22 dBc at 7.656 GHz.