Experimental investigation of the input-impedance characteristics of an antenna in a rectangular waveguide

The input impedance of a monopole antenna in a rectangular waveguide is investigated experimentally. It is found that theoretical results based on the assumption of a sinusoidal current distribution are in good agreement for monopole lengths up to about 0.6 of the guide height and about 1/4 ¿0. For longer monopoles, a more accurate theory should be sought.