A Transformer-Based Current-Reuse QVCO With an FoM Up to −200.5 dBc/Hz

A high performance X-band quadrature voltage-controlled oscillator (QVCO) is presented. The transformer feedback topology is proposed to combine with the interactive self-switching current bias technique, which can achieve a low phase noise while maintaining low power consumption simultaneously. The measured phase noise is −123.84 dBc/Hz at 1-MHz offset with a 10.56 GHz carrier frequency and the IQ phase error is less than 1.9°. Under a power consumption of 2.4 mW, the proposed QVCO in 0.18-
$ {\mu }\text{m}$
CMOS achieves an excellent FoM up to −200.5 dBc/Hz, which is among the best compared with previous works using a similar technology.