A 2–8 GHz Wideband Dually Frequency-Tuned Ring-VCO With a Scalable ${\rm K} _{\rm VCO}$

A 2-8 GHZ wideband dual-tuned ring voltage- controlled oscillator (VCO) has been designed and fabricated in TSMC 65nm CMOS process. Using a 6-bit digital-to-analog converter (DAC) that provided the V coarse, the entire frequency range was evenly divided into 64 sub-bands. Next, the oscillation frequency was finely tuned by V fine to control the strength of the latches in the delay cell of the VCO. In addition, 4-bit latch bank was used in each delay cell to ensure that the K VCO was scalable. The active silicon area was 0.038 mm² and the power consumption was 1.7 and 6.8 mW at 2 and 8 GHz, respectively.