Evaluation of input impedance of cylindrical doublet antennas

By means of electrostatics and transmission line theory, the equivalent transmission line method has been complemented and corrected so that to be used to evaluate the input impedance of cylindrical doublet antennas. A more accurate calculation formula has been developed,in which the loss along the equivalent transmission line and the end-effects have been taken into account. Numerical and experimental results obtained show that this corrected formula is adaptable to thick cylindrical antennas and gives more accurate result with less mathematical complication than both Hallen´s integral equation method and Schelkunoff´s biconical antenna theory.