Design of Low Phase-Noise Oscillator Based on a Hairpin-Shaped Resonator Using Composite Right/Left-Handed Transmission Line

In this letter, a low phase-noise microwave oscillator based on a hairpin-shaped resonator (HSR) using a composite right/left-handed transmission line (CRLH TL) is proposed. The proposed HSR consists of the conventional transmission line (CTL) and the CRLH TL. In order to obtain the high- Q factor, an electric field is concentrated on the CRLH TL, and then the CRLH TL provides a low loss due to a slow wave effect. The proposed HSR has a very compact size of 0.105 λ_g ×0.19 λ_g. An oscillator based on the HSR was designed, fabricated and measured. At the oscillation frequency of 4.95 GHz, the measured phase noise is -120.5 dBc/Hz at 100 kHz offset with 4.93 dBm output power.