Determination of Attenuation from Impedance Measurements

Heretofore, the determination of attenuation from impedance measurements has been applied to cases in which the reflections from the attenuator terminals were negligibly small. In the proposed method no restrictions are placed upon the attenuator except the requirement that it be a linear, passive, four-terminal network. The dissipative and reflective components of attenuation ADand ARare measured separately. ADis shown to be a function of the efficiency of the attenuator. The efficiency is determined from reflection coefficient measurements of the short-circuited attenuator. ARis determined from a single voltage-standing-wave ratio measurement of the attenuator when terminated in a matched load. Experimental data show close agreement with an independent method of determining attenuation.