A 7GHz wideband self-correcting quadrature VCO

A 4.0 to 6.6GHz self-correcting quadrature voltage controlled oscillator (QVCO) with phase compensation loop is implemented in a 65nm CMOS process. The topology couples IQ oscillation signals of two LC-VCOs, a phase shifter, and buffers with circular configuration. This paper introduces the idea to obtain low phase noise and accurate IQ phase quadrature oscillation signal, by employing phase compensation loop to correct the IQ phase error. The self-correcting QVCO achieves the IQ phase error less than a degree, and 1MHz offset phase noise -107dBc/Hz at 6.9GHz.