Low‐power divide‐by‐4 injection‐locked frequency divider using an inductive resonating technique

Abstract

An injection‐locked frequency divider (ILFD) with the low‐power divide‐by‐4 feature for K‐band applications in a 0.18 μm CMOS process is reported in this letter. Output differential signals (f0 = 4f0‐3f0) are obtained by the third‐harmonic signals (3f0) from the free‐running core mixing with injection signals (4f0) through injection transistors in the proposed ILFD. This improves the locking range and saves power consumption by employing an inductive resonator technique and double cross‐coupled transistor pairs without the help of varactors. For the proposed ILFD, the measured free‐running frequency is 5.126 GHz and input injection frequencies at an input power level of 0 dBm are from 19.4 to 21.4 GHz. From a supply voltage of 1.5 V, the proposed ILFD core only dissipates 4.2 mW.