Frequency and Pattern Reconfigurable Antenna Using Double Layer Petal Shaped Parasitic Structure

In this brief, a frequency and pattern reconfigurable antenna using double layer petal shaped parasitic structure loaded with PIN diodes is proposed. The double layer parasitic structure proposed in this brief makes it possible to realize pattern reconfigurable function at a wider range of frequency. The operating frequency of the antenna can be tuned continuously and the radiation pattern can be controlled to scan from 0(degrees) to 360(degrees) in steps of 25.7(degrees). First, an omnidirectional antenna consisting of four bending dipoles is designed and varactor diodes are loaded on the antenna to realize frequency dynamic manipulation. Then petal shaped parasitic structures with PIN diodes loaded at the center gaps are placed around the omnidirectional antenna to achieve pattern reconfiguration with high angle resolution in 360(degrees) range. The parasitic structures are distributed on both sides of the dielectric plate, which can be combined to broaden the tunable frequency range of the pattern reconfigurable antenna effectively. Finally, a prototype antenna is fabricated and measured. The center frequency of the antenna can be tuned from 2.2 GHz to 2.52 GHz and the radiation pattern can be manipulated to change at intervals of 25.7(degrees) in the whole horizontal plane.