3 mW W-band CMOS injection-locked frequency divider with 23.5-GHz locking range

A low-power and wide-locking-range W-band divide-by-2 direct injection-locked frequency-divider (DILFD) using 90 nm CMOS technology is reported. To enhance the operation frequency, distributed LC network is used as the load of the crossed-coupled transistors. To improve the input sensitivity, a power matching network is included at the injection terminal of the switch transistor. In addition, to enhance the frequency locking range, body bias technique (i.e. a body resistor in conjunction with a zero body-source bias) is adopted in the switch transistor to reduce its threshold voltage. The result shows that a wide locking-range of 23.5 GHz (28.9%) was achieved. The DILFD can be operated at a low input power of −35 dBm, one of the best input sensitivity ever reported for a W-band divider. The power consumption of the DILFD was 3 mW.