20 GHz CMOS injection-locked frequency divider with variable division ratio

An injection-locked frequency divider (ILFD) with variable division ratio, controlled by the input offset voltage, was realized using a 0.13 /spl mu/m CMOS technology. In this report, the controllable division ratios were made from 2 up to 16 with an input AC signal of 10 GHz, by changing the input DC offset voltages. This divider also performs division ratios of 2, 4, 6 and 8 with a wide-locking range up to 20 GHz at 2.5 GHz self-oscillation. The DC supplied voltage of this circuit is only 2 V and the dividing capability can reach 20 GHz.