Determination of the equivalent circuit of coaxial line-antenna junctions

Summary form only given. Both theoretical and experimental aspects of the problem of determining the equivalent circuit of the open-ended coaxial line or waveguide are considered. From the practical point of view, the input impedance determined by the equivalent circuit of the junction between the coaxial line and an external structure is sufficient to solve the internal problem of a coaxial feed line. The input impedance of junctions between the coaxial transmission line and several planar antennas, used as sensors, is solved with the use of the concept of the terminal region. The properties of the eigenfunctions in the coaxial region are used to complete computation. The matching technique is used at the aperture for fields in the coaxial line and in the structure being fed by the line. In the experimental part, the theoretically determined equivalent circuit was compared with that obtained from measurements using a network analyzer.<>