A Fully-Integrated 5-GHz Frequency Synthesizer

This paper presents a 20-channel, 4.850-5.325 GHz PLL based frequency synthesizer implemented in a production SiGe BiCMOS technology. The circuit is fully integrated, including the loop filter capacitor and VCO. A fast settling time of 10 usec is measured with a reference frequency of 12.5 MHz. Preliminary wafer-level tests indicate a phase noise below -100 dBc/Hz at a 1-MHz offset. The chip dissipates 255 mW from a 3.3-V supply and occupies an active area of 2 mm².