Study on impedance tuner and its use in voltage controlled oscillator nonlinear parameter test

This paper introduces the nonlinear frequency pull mechanism of voltage controlled oscillator (VCO), the operation principle of impedance tuner, and presents a frequency pull test method based on impedance tuner, which provides a valid method to use load-pull technology to solve the measurement problem of nonlinear correlative characteristic of device under test (DUT). The measurement results show the feasibility and effectiveness of this method.