Compact Circular Reconfigurable Antenna for High Directivity and 360° Beam Scanning

A compact reconfigurable antenna with high directivity and 360° beam steering is proposed for 5.8 GHz band application. The concept incorporates via-grounding technique around a circular patch that is shorted with a matching patch, surrounded by a combination of edge-grounded sector patches and arc strips. The matching patch is utilized to improve the impedance matching and lower the resonance frequency. Six beam-steerable states are achieved using 12 p-i-n diodes. Compared to other reconfigurable antennas for similar applications, the presented design has a more compact size (diameter of 1.95λ
_g
) and profile of 0.17λ
_g
, where λ
_g
is the wavelength at resonance, while maintaining a high gain (8.1 dBi), front-to-back ratio (18 dB), and efficiency (84%).