Morehead State University
Integration of Left-Handed Materials with RF MEMS Devices
Institution
Morehead State University
Faculty Advisor/ Mentor
W. Grise; B. Cetiner
Abstract
The results of research on the integration of two exciting technologies in the microwave electronics discipline, viz., radio-frequency microelectromechanical systems (RFMEMS), and negative refractive index metamaterials (NRM). RF-MEMS technology has made possible the tailoring of the responses of microwave frequency circuits by means of microscopically small switches. When these tiny switches are actuated mechanically, it becomes possible to create alternative realizations of such standard microwave circuit elements as phase shifters, periodic filters, and antenna elements that are much smaller and consume less power than conventional RF circuits. Negative refractive index metamaterials display negative dielectric permittivity and negative magnetic permeability. When propagating through these structures, electromagnetic waves show properties such as backwards power flow, and the ability to focus subwavelength radiation. Thus, an NRM focuses both propagating waves along with evanescent waves that originate from an object, so bypassing the conventional diffraction limit – so-called perfect lensing. The novel contribution of this research is that for the first time both of these technologies are being integrated together, thus combining the tunability and microscopic control of propagation characteristics due to RF-MEMS with the unusual lensing properties of NRM elements. The research has utilized the facilities of Morehead State University’s Space Science Center to design and simulate the circuitry and to test the resulting circuits. The circuits include a microstrip transmission line as a proof of concept, as well as a dual-band branch-line coupler, with the dual frequencies separated by non-harmonic intervals; synthesis with such intervals is difficult for conventional microwave circuits.
Integration of Left-Handed Materials with RF MEMS Devices
The results of research on the integration of two exciting technologies in the microwave electronics discipline, viz., radio-frequency microelectromechanical systems (RFMEMS), and negative refractive index metamaterials (NRM). RF-MEMS technology has made possible the tailoring of the responses of microwave frequency circuits by means of microscopically small switches. When these tiny switches are actuated mechanically, it becomes possible to create alternative realizations of such standard microwave circuit elements as phase shifters, periodic filters, and antenna elements that are much smaller and consume less power than conventional RF circuits. Negative refractive index metamaterials display negative dielectric permittivity and negative magnetic permeability. When propagating through these structures, electromagnetic waves show properties such as backwards power flow, and the ability to focus subwavelength radiation. Thus, an NRM focuses both propagating waves along with evanescent waves that originate from an object, so bypassing the conventional diffraction limit – so-called perfect lensing. The novel contribution of this research is that for the first time both of these technologies are being integrated together, thus combining the tunability and microscopic control of propagation characteristics due to RF-MEMS with the unusual lensing properties of NRM elements. The research has utilized the facilities of Morehead State University’s Space Science Center to design and simulate the circuitry and to test the resulting circuits. The circuits include a microstrip transmission line as a proof of concept, as well as a dual-band branch-line coupler, with the dual frequencies separated by non-harmonic intervals; synthesis with such intervals is difficult for conventional microwave circuits.