Characterization and Testing of Adaptive RF Metamaterial Structure Using MEMS

Abstract

Metamaterials are materials with periodic, sub-wavelength inclusions believed by some to generate responses that behave electromagnetically like effective mediums. This behavior provides the capability to synthesize materials with special parameters that will allow for size reduction of existing devices as well as the creation of new devices with unique capabilities. A key limiting factor for metamaterials, however, is the restriction of the special parameters to a small frequency band. To overcome this limitation, a microelectromechanical systems (MEMS) cantilever-beam device is placed over the gaps of a pair of split ring resonator (SRR) particles designed to operate in the radio frequency (RF) regime. Along with a wire lattice, the SRR particles are believed by many to generate an effective medium with a negative index of refraction over a small frequency band. The variable capacitors change the capacitance of the SRRs and shift the resonant frequency of the device. Efforts to predict and measure the behavior of this device are critical to the design effort. This paper demonstrates the techniques employed to model and test the electromagnetic properties of this device.