Rounded-edge bow-tie antenna for wideband mobile direction finding system

A novel relatively small wideband antenna is introduced for the mobile application of direction finding (DF) systems covering the frequency range from 150 MHz to 3 GHz. The proposed directional wideband antenna is a rounded-edge directed bow-tie antenna which is electrically small when considering at lower operating frequencies. A good agreement is obtained between the simulation and measurement results of the designed antenna. The performance of the antenna for DF applications is verified both in anechoic chamber measurements and in open field measurements. In addition, in open field DF measurements the proposed antenna is compared with a commercial antenna. During the tests, one of the angle of arrival estimation technique based on phase differences of the signal at the antenna elements, interferometer method, and combination of the phase differences and amplitude values of the captured signal were used. As well as, k-means clustering used to reduce undesired error due to environmental effects.