Characteristics of TV transmitting batwing antennas

All of the characteristics of the batwing radiator, which is the heart of the superturnstile antenna system, are theoretically calculated by using the moment method. The matching condition is obtained on the basis of the characteristics in the cases of changing the shape of the jumper and of changing the distance between the support mast and the antenna elements. In this paper, a comparative study on the results of theoretical analysis and actual measurements was conducted as to whether or not the construction of the batwing antenna could be simplified by eliminating the element at its central part, without detracting its favorable characteristics. Next, regarding the mutual radiation impedance when arranged as a broadside array, a theoretical analysis was made according to the moment method, and the results were compared with measured values. As a result, in the case where this antenna was positioned at a distance exceeding full wavelength, the value was in the order of a few ohms, and it was found that mutual radiation coupling effect was small.