Independent Control Function for Concurrent Dual-Band VCO

This letter presents a concurrent dual-band voltage-controlled oscillator (VCO) with independent control of the two oscillation frequencies based on a common dual-band bandpass filter (BPF). The odd- and even-mode resonant frequencies of the BPF can be independently tuned to realize the concurrent dual-band VCO. Based on the principle of the flexible tuning characteristics, analytical equations are obtained to introduce a method for circuit size reduction and tuning range extension. The measured results show that the two oscillation frequencies cover a tuning range of 1.59-1.802 and 3.314-3.42 GHz, respectively.