A Millimeter-Wave 90-nm CMOS Self-Mixing Frequency Divider

This letter presents a millimeter-wave 90 nm CMOS divide-by-four frequency divider using self-mixing technique. The output of the push-push oscillator mixes with the input signal, and the resulting intermediate frequency signal locks the fundamental oscillation frequency of the oscillator at exactly one-fourth of the input signal frequency. The frequency divider is implemented in TSMC 90 nm 1P9M digital CMOS technology and the overall die size is 0.91 mm times 0.53 mm. For low-power mode, the divider consumes only 0.8 mW with a 0.8 V supply voltage, and the measured locking range is 300 MHz. For normal mode, the divider consumes 2 mW with a 1 V supply, and the locking range is extended to 1100 MHz. The operating range of the divider covers from 46.1 to 52.8 GHz with varactor tuning and band switching.