Tuning Swiss roll metamaterials

摘要

The 'Swiss roll' metamaterial is well suited to operation in the radiofrequency range because ithas a low resonant frequency, a strong magnetic response and is electrically very small.However, the elements have to be individually produced, leading to significant variation in theresonant frequency. It is therefore necessary to tune the elements to a target frequency. Threemethods for achieving this are described: attaching capacitatively coupled sleeves or discretecapacitors for static tuning, and using a varactor diode to provide electrically controllabletuning. In the last case, the switching time is found to be <1 ms, making dynamic tuning a realpossibility.