Three-terminal immittance measurements by standing-wave methods at V.H.F. and U.H.F.

The problems associated with the measurement of 3-terminal immittances at v.h.f. and u.h.f. are discussed. The relationships between various measured immittances and the elements of a 3-terminal load are derived. Balanced standing-wave meters, which were used in the measuring techniques at frequencies from 100 to 1200Mc/s, are described. The results of measurements, which confirmed the theory within experimental accuracy, are given. It is shown that an equivalent delta network for a 3-terminal load may be derived from three measurements. With a measuring line having a residual v.s.w.r. of 1.01, an accuracy within the order of ±5% for the most important element in a 3-terminal immittance has been obtained.