Methodology to Reduce the Number of Switches in Frequency Reconfigurable Antennas With Massive Switches

This paper proposes a new method for decreasing the complexity of reconfigurable antennas (RAs) with massive switches while increasing their reconfigurability. The proposed method is performed by removing the less important switches of an RA. Therefore, the RA only has a few important switches that have strong influences on the reconfigurability. The importance of a switch is evaluated by the minimum percentage of useful configurations (PUC). A monopole-type omni-directional frequency RA with 85 uniformly-distributed switches is optimized in this paper. For this type of antennas, a reflection coefficient less than -20 dB and a gain greater than 0 dBi at the same frequency makes a useful configuration. After reducing the switch number from 85 to 15, the complexity of the RA is greatly decreased while the reconfigurability is increased by more than 100 times within the band of 2 to 7 GHz. With only 15 optimally deployed switches, the PUC is significantly increased. Therefore, it is easy to find out the states of the switches to let the frequency RA work well at different frequencies. The results show that the proposed method is an efficient way to design RAs with switches in an optimal deployment.