A Shunt Technique for Microwave Measurements

A new method of measuring low-loss quantities at microwave frequencies, which employs a Iossy shunt structure, is described. The additional loss introduced thereby reduces the excessively high VSWR's to values lying in the measurable range. The relevant information is abstracted from the data in a precision manner independent of the parameters of the shunt structure itself. Applications are made to the measurement of low-loss dielectric constants, structures with shunt representations such as certain bolometer elements, attenuation constants, and VSWR's of slightly Iossy variable short circuits. Physical realizations of such shunt structures are discussed.