Characteristics of Curtain Antennas for HF Broadcasting

Abstract

A folded dipole antenna placed in front of a reflecting screen is usually used as the wideband radiator of curtain antennas for HF broadcasting, and the bandwidth radiated has been increased by using a multiple-wire structure for the dipole. This paper uses the moment method analysis to evaluate some characteristics of the antenna elements, such as their frequency and mutual coupling. Calculating and comparing the bandwidths of six antennas with multiple-wire dipoles confirms that this structure increases the bandwidth of the dipole. This paper also describes how the calculated mutual coupling of two-pair folded dipoles placed in both sides of the screen depends on the screen parameters, and it describes the relationship between antenna structure and the radiation pattern.