A Low-Voltage 30-GHz CMOS Divide-by-Three ILFD With Injection-Switched Cross-Coupled Pair Technique

This paper presents the design of a divide-by-three frequency divider operating at 30 GHz with an injection-switched cross-coupled pair topology. A wider locking range as well as a lower operation voltage can be achieved because of this newly proposed topology. The divider is implemented in a 90-nm standard CMOS process. The total locking range of the divider core is 4.5 GHz with a power consumption of 2.85 mW from a supply voltage of 0.5 V. The total power consumption of the buffers is 2.65 mW from a supply voltage of 1.0 V. The measured output phase noise is -141 dBc/Hz at 1-MHz offset when the input referred signal has a phase noise of -131 dBc/Hz at 1-MHz offset from 30 GHz. The phase-noise difference of 10 dB is close to the theoretical value of 9.5 dB for division-by-three. The total chip size is 0.48 mm
²
, and the divider core size is only about 0.14 mm
²
.