A dual-band SiGe BiCMOS offset PLL for EGSM 900 MHz and DCS 1800 MHz cellular transmitters

A fully integrated dual-band offset phase-locked loop (OPLL) for EGSM 900 MHz and DCS 1800 MHz standards is presented. The system is implemented in a 0.35/spl mu/m SiGe BiCMOS technology with f/sub T/ of 60 GHz, featuring integrated colpitts VCOs with above-IC thick copper spirals. Simulation results indicate that all EGSM and DCS specifications are met over a temperature range from -20 to 80 /spl deg/C and power supply range from 2.7 to 3.3 volts. The chip consumes 112 mW and 114 mW in the EGSM and DCS bands respectively.