Reconfigurable Beamwidth Antenna Based on Active Partially Reflective Surfaces

This letter presents a new method to design a new reconfigurable antenna by using an active cylindrical electromagnetic band-gap (EBG) structure for wireless communication systems. The antenna provides a reconfigurable elevation beamwidth while the azimuth radiation pattern maintained omnidirectional. The EBG structure that is composed of periodic discontinuous metallic strips and PIN diodes behaves as an active partially reflecting surface (PRS). By changing the diode states, the reflection coefficient of the structure is controlled so that the radiation beamwidth and directivity of the antenna can be reconfigured. To validate the proposed concept, the final prototype is fabricated, and measurement results are also presented and discussed.