A 15-GHz broad-band /spl divide/2 frequency divider in 0.13-μm CMOS for quadrature generation

This letter presents a 0.13-μm 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 19GHz, although the available tuning range of the signal source limited the experimental verification to the interval 11-15GHz, featuring a 31% locking range. The divider dissipates 3mA from a 1.2-V power supply.