A Wide-Angle Scanning Tightly Coupled Antenna Array with a Microstrip-to-Slotline Feeding Network

Abstract

We present an ultra-wideband tightly coupled array with an integrated feeding structure and a wide-angle scanning superstrate layer. This antenna is fed by a simple microstrip-to-slotline structure, which can significantly reduce the complexity and the cost of the tightly coupling array. The superstrate layer consists of two frequency selective surfaces (FSSs), which can efficiently improve the scanning angle. The tightly coupled dipole array (TCDA) with 16 ×16 elements has a bandwidth of 5.13:1 (0.75-3.85 GHz) and can respectively scan its beams to ±70 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">o</sup> in E plane, ±70 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">o</sup> in D plane, and ±60 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">o</sup> in H plane. The profile of the array is only 0. 118λ at the lowest operating frequency. The proposed array has advantages of ultra wi de band, wide scanning range, low profile, low cost, and easy fabrication.