Novel methods for phase noise reduction and harmonic suppression in a planar oscillator circuit based on split ring resonators

In this paper, we describe a novel microwave oscillator incorporating a CPW-based split ring resonator (SRR) as a resonant component of the circuit. The high-quality (Q) factor and spurious-free SRR contribute to phase noise reduction as well as the harmonic tuning of the oscillator circuit in a very small chip area. The fabricated 5.5-GHz oscillator showed an output power of 2.774 dBm with a second harmonic suppression of −43.04 dB and phase noise of − 100.8dBc/Hz at 100 kHz offset. The proposed oscillator is believed to be the first application of a metamaterial to the performance enhancement of a microwave active device.