A Nested-Spring Metamaterial Unit Cell for Broadband Mechanically-Tunable Effective ∊

This paper presents a novel nested-spring metamaterial unit cell that achieves broadband mechanically-tunable effective permittivity using compression and expansion of the spring-based unit cell structures. These structures are shown in simulation to be capable of producing relative effective permittivities ranging from 1.06 to 7.04 at the low end of the frequency range, with variation less than 10% from 2 MHz to 106 MHz. At the upper end of this frequency range, the electrical size of the unit cells is λ/57.