Parasitic conscious 54 GHz divide-by-4 injection-locked frequency divider

Abstract

An injection-locked frequency divider (ILFD) is utilized to divide the frequency of a voltage-controlled oscillator (VCO). We propose an ILFD that can be directly connected to a VCO by minimizing the input capacitance of the input nodes. The capacitance is reduced by limiting the number of MOSFETs connected to the injection nodes. We fabricated a 54 GHz divide-by-4 ILFD using 65 nm CMOS technology whose core area is 60 × 90 μm2. By limiting the number of driven MOSFETs and reducing the parasitic capacitance, a locking range of 430 MHz is achieved at a -20 dBm input. The power consumption is 21 mW with a 1.2 V supply and the phase noise is -120 dBc/Hz at a 1 MHz offset.