Untilted edge slot antennas excited by T-shaped wires

Abstract

Abstract An effective method is proposed to excite the untilted edge slot antennas. In the proposed method, two T-shaped wires are placed at both sides of each untilted slot. Two legs of each T-shaped wire are connected to the waveguide walls, while the third leg is open. One of the T-shaped wires connects the upper broad wall of the waveguide to the narrow wall of the waveguide which contains the slots. Similarly, the other T-shaped wires connect the lower broad wall of the waveguide to the narrow wall of the waveguide that contains the slots. The phase reversal between the adjacent slots can be accomplished by changing the orientation of the T-shaped wires. It is shown that the arm lengths of the connected wires can be employed as a parameter to control the radiated power by the slots. Furthermore, the arm lengths of the open wires can be selected properly to control the dynamic range of the equivalent normalized susceptance associated with each untilted slot antenna. To validate the effectiveness of the proposed antennas, two linear arrays consisting of 11 slots have been designed, implemented, and tested. The simulation and the measurement results of the designed arrays show that for the proposed untilted edge slot antennas, the dynamic range of the equivalent normalized susceptance is improved significantly which leads to a straightforward design process with no requirement to resort to any time-consuming tuning process.