Tunable split-ring resonators for nonlinear negative-index metamaterials.
In this paper, we present the design of a reconfigurable antenna based on the dynamic tuning of a planar system that consists of a loop antenna, metamaterial spilt ring resonators (SRRs), and heterojunction photo transistors (HPTs). Simulation results of a unit cell of SRRs indicate that the resonant frequency of the SRRs shifts from the original of 65 GHz to 76 GHz with a HPT introduced into the gap of the ring. In combining the SRRs and HPTs with a loop antenna, a tuneable antenna system is designed having a tuning range from 41.5 to 44 GHz. In addition to the ability to tune the planar antenna, it offers the advantage of being compact and easy to integrate, which ultimately reduces signature and offers more flexibility for army platforms.