A 6-GHz dual-modulus prescaler using 180nm SiGe technology

A 6-GHz divide-by-3/4 prescaler for fractional-N frequency synthesizers is presented in this paper. Optimization in the power consumption is carried out to ensure a high efficiency. Meanwhile, the critical cells, current-mode-logic (CML) building blocks, are optimized for high frequency and low power consumption. A prototype has been implemented in 180nm SiGe BiCMOS technology offered by Tower Jazz. The silicon area for the divide-by-3/4 prescaler is only 40 μ m × 50 μ m. The maximum operating frequency can reach 6-GHz, with 7.92mW power consumption in 1.8V voltage supply.