Frequency and Radiation Pattern Reconfigurability of a Multi-Size Pixel Antenna

Pixel reconfigurable apertures constitute one of the most adaptable structures regarding antenna reconfiguration, being capable to achieve frequency and pattern compound reconfiguration. However, pixel antennas require a large amount of switches (typically above 100) that severely impact the antenna efficiency, complexity, cost and reconfiguration time. This paper presents a novel technique to mitigate the inherent complexity of pixel antennas by including multiple sized pixels divided over driven and parasitic regions. The technique has been applied to a planar monopole architecture leading to a low-complexity prototype of small dimensions and requiring only 12 switches. Its reconfiguration properties have been fully characterized through exhaustive measurements. Frequency reconfiguration is achieved from 1 GHz to 6 GHz with simultaneous beam-steering capabilities, being capable of synthesizing at each frequency an omnidirectional pattern and up to 5 directive patterns steered towards directions covering an angular range of almost 180°.