Analysis of the Field Mode of the Alford Slot Antenna for Television Broadcast Communication

Cylindrical slot antenna is widely used in TV broadcast antenna because of its good characteristics of directional pattern, simple structure and easy installation. Among them, a typical cylindrical slot antenna is Alford slot antenna. In this paper, the Alford slot antenna of two different feeding modes is designed and analyzed, especially the field mode under the two feeding modes is analyzed. The simulation results show that, compared with the external feeding, the internal feeding of the cylinder is equivalent to setting the impedance transformation part inside the antenna, which makes the antenna and the feed part become a whole and the structure is simpler. At the same time, it still has a wide impedance bandwidth and good directional characteristics.