Adaptive metamaterial antenna using coupled tunable split-ring resonators

A planar array of coupled split-ring resonators (SRRs) shows many resonances over a broad frequency band at which the structure efficiently emits waves. The mode splitting due to coupling offers an unprecedented way for configuring the radiation pattern of the SRR array. It is shown that specific radiation patterns that include dipolar and quadrupolar oscillation patterns can be constructed by varying the self-impedance of the resonators. Presented is an experimental demonstration based on this concept using electronically tuned SRRs. With this setup, the radiation pattern at a given frequency can be adjusted using a DC voltage command. The proposed structure is an efficient and compact alternative to traditional electronic beam-steering antennas.