A Novel Concurrent Dual-Band Oscillator Based on a Single Ring Resonator

A concurrent dual-band oscillator using a single ring resonator is proposed in this letter. This novel oscillator employs a stepped-impedance (SI) which exists two orthogonal resonant modes, to provide a dual-band operation. Specifically, the new planar oscillator is designed with two transistors operating at two different frequencies as negative resistance devices, which compensate for the resonator losses independently, for making the resonator unstable. Then, it simultaneously outputs two oscillation frequencies by two load matching networks. Compared with the conventional concurrent dual-band oscillators, the proposed one reduces harmonics mixing of the frequencies and outputs purer spectrums.