An HIS-Based Spiral Antenna for Pattern Reconfigurable Applications

Abstract

Single arm rectangular spiral antenna with four open circuit switches over a high-impedance surface (HIS) is proposed for pattern reconfigurable applications. The HIS plane without vias is utilized to achieve a low-profile antenna design with a net thickness of 5.08 mm. This is equivalent to ~ lambda <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">o</sub> /17 for the intended operating frequency of 3.3 GHz. By using the possible sixteen switching combinations a near 360deg beam steering is achieved, and the switched beams do not have a polarization variation from one pattern to another. The realized pattern reconfigurable antenna has both the tilted (thetas <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">max</sub> ges 25deg) and axial (5deg < thetas <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">max</sub> < 10deg) beams, which have an average directivity of 6.9 dBi.