A Review of and New Results for Broadband Antennas for Digital Terrestrial Broadcasting: The Modified Batwing Antenna

摘要

Digital terrestrial broadcasting services are in the Japanese UHF band of 470 to 770 MHz. The bandwidth of the UHF-TV channel is 6 MHz. The batwing radiator, which is at the heart of the super-turnstile antenna system for FM and VHF-TV broadcasting, has broadband characteristics. In this paper, we investigated a modified batwing antenna for UHF digital terrestrial broadcasting. The characteristics of the two- and four-element modified batwing antennas, with an infinite or a finite wire reflector, were calculated using NEC-WIN Pro. We evaluated the characteristics of these antennas in the Japanese UHF-TV broadcasting band. A broadband input impedance and high gain were obtained in the calculation and the measurement. A four-plane arrangement of parallel batwing antennas was also examined for directionality. The batwing element was arranged in parallel,and the feed interval was a half-wavelength. High gain and wideband characteristics were obtained with simple power-supply construction. This antenna has sufficient characteristics for use as the transmitting antenna for digital terrestrial broadcasting stations and repeater stations in the Japanese UHF band.