A wideband unidirectional antenna array element with stable radiation pattern

A modification of the famous Bow Tie antenna element for wideband Direction-Of-Arrival estimation antenna arrays is designed. A broadband impedance match from 5 GHz to 14.5 GHz corresponding to a 97% bandwidth, as well as a very stable radiation pattern over a 37% bandwidth from 5.5 GHz to 8 GHz is achieved. A method for pattern stabilization using parasitic edge currents is shown. In addition the proposed design uses a double layer substrate and hence aims at direct integration of the feed network and analog RF circuitry directly into the antenna array. The particular design is suited for low-cost integration and optimized for a wireless high-precision localization system.