An HIS-Based Spiral Antenna for Pattern Reconfigurable Applications

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 ∼ λ0/17 for the intended operating frequency of 3.3 GHz. By using the possible sixteen switching combinations a near 360° 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 (θmax ≥ 25°) and axial (5° < θmax > 10°) beams, which have an average directivity of 6.9 dBi. © 2009 IEEE.