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.