A 15-GHz Broad-band ÷2 Frequency Divider in 0.13-µm CMOS for Quadrature Generation

This letter presents a 0.13-ìm CMOS frequency divider realized with an injection-locking ring oscillator. This topology can achieve a larger input frequency range and better phase accuracy with respect to injection-locking LC oscillators, because of the smoother slope of the loop gain phase-frequency plot. Post layout simulations show that the circuit is able to divide an input signal spanning from 7 to 19 GHz, although the available tuning range of the signal source limited the experimental verification to the interval 11-15 GHz, featuring a 31% locking range. The divider dissipates 3 mA from a 1.2-V power supply.