Implementation of Low Phase Noise Wide-Band VCO with Digital Switching Capacitors

This paper presents a low phase noise of the complementary cross-coupled voltage-controlled oscillator, which oscillates at a range of 3.64 ~ 5.37 GHz. This VCO utilizes switching capacitor modules in which eight channels are able to be selected. Moreover, MOS varactors are used as fine tuning. The fully integrated VCO provides excellent performance. The bandwidth of frequency is 1.73 GHz and the tuning range is 38%. The power dissipation of the core circuit is 13.7 mW under 1.8 V supply and phase noises all are smaller than -122 dBc/Hz at 1 MHz offset. This VCO was made by TSMC 0.18 mum 1P6M CMOS standard process and the chip area is 0.96 times 0.83 (mm²).