A resonator impedance de-embedding procedure

In many contemporary high-frequency circuits, a dielectric resonator is coupled to a microstrip line section, the ends of which constitute a two-port. A detailed procedure is presented for recovery of impedance values associated with the resonator from S-parameter measurements on the two-port with a vector network analyzer. The procedure is suitable for computer-assisted numerical processing, takes into account lossy propagation and moderate impedance vagaries along the microstrip line, and includes discontinuities in the coax-to-microstrip transitions. Resonant frequency, unloaded Q, and effective coupling coefficient can be determined subsequently from the de-embedded impedance values