Design of low phase noise VCO using complimentary split ring resonator

We have described a 5.8 GHz VCO using the High-Q resonator of the CSRR structure and the negative resistance circuit of the CRLH-TL target for ISM band wireless applications. Wider tuning range and lower phase noise than the conventional VCO have been obtained by this structure. Powered by a 1.2 V supply, the VCO has consumed 56 mA current with measured phase noise of -114.33 dBc/Hz at 100 kHz offset of the 5.8 GHz carrier. As a result, the VCO has been achieved a FOM of -191.6, which is one of the best reported to date.