Technical memorandum: Sensitive method of measuring dielectric losses at microwave frequencies

Changes in the cavity/waveguide parameters are rather small when low-loss dielectric materials are measured by the usual resonant or transmission methods. However, such parameters can be enlarged by using the H-plane loading techniques. The method described in the paper uses an H-plane dielectric-loaded cavity. The experiments are carried out for measuring the dielectric losses of polymethyl methacrylate and polystyrene sheets around 7 GHz. The results obtained are in agreement with the published results.