5 GHz Monolithic VCO with prescaler using BiCMOS SiGe technology

Bipolar VCO and prescaler for 5GHz low cost wireless applications are presented. These circuits are implemented in a 0.35?m BiCMOS SiGe process (FT=45GHz). Phase noise value for a 4.82GHz bipolar VCO is ?12ldBc/Hz at 1MHz frequency offset. Based on CML architecture, a 5GHz 7/8 prescaler is designed and tested. These circuits are the two HF critical buildings blocks in designing wireless communication systems, and in particular, PLL frequency synthesisers.