The measurement of attenuation along the arms of a travelling wave V-antenna

The measurement of attenuation along the arms of the antennas is based on the measurement of the input impedance of the antenna. In these measurements, it is assumed that the cable feeding the antenna is sufficiently well matched to the antenna input impedance for one to consider only the first forward wave, the first reflected wave, and the second forward wave, in the analysis. This assumption is verified numerically. A description is also given of a technique for the feed arrangement. This feed technique is based on the electromagnetic field properties of strip lines. By connecting the feed cable to the antenna using closely spaced striplines, the outer conductor of the coaxial cable lies outside the electromagnetic field. It was found that the coaxial cable could be moved about considerably without any affect on the gain, the input impedance, or the polar diagram of the antenna.<>