Metamaterial Research at Michigan State University
Current Projects
Negative Permeability Metamaterial
Metamaterials with negative permeability are designed based on topology optimization. The formulation is based on the design of a thin layer of copper printed on a dielectric, rectangular plate of fixed dimensions. An effective media theory is used to estimate the effective permeability. New metamaterial concepts are uncovered, beyond the classical split-ring inspired layouts.
In-situ Optimization of Metamaterial-inspired Antennas for Miniaturization
mini antenna
A genetic algorithm is used to optimize a metamaterial-like pattern adjacent to an antenna to enhance the antenna’s performance. As an example, the technique is used for miniaturization purposes, achieving a sevenfold reduction in antenna area over a conventional loop antenna.
Periodic Dielectric Materials for Transmission/Reflection Characteristics
periodic dielectric
A topology optimization method is used to design two dimensional
periodic structures with desirable transmission properties by distributing
two materials of different permittivity over a rectangular representative cell.
Waveguides and Microstrip Filters Using Metamaterials
A technique is introduced for designing band-stop waveguide filters by optimizing a grid of metallic pixels on a dielectric sheet placed longitudinal to the waveguide axis. By using topology optimization and a genetic algorithm, compact broadband waveguide filters may be produced that are easy to fabricate at low cost. Measured and simulated performance show strong rejection in the stopband with a rapid roll off at the band edges, and low insertion loss outside the stopband.
Antennas using Metamaterials
CSRR antenna
Miniature patch antennas are designed based on complementary split ring resonators (CSRR). A genetic algorithm is used to optimize geometric parameters of CSRRs for low reflection coefficient at the target frequency. A size reduction of 90% is achieved without degrading the antenna performance, with reflection coefficient maintained lower than -15dB.
Tunable and Reconfigurable Metamaterials using Lumped Components
chip antenna
Miniaturized tunable planar monopole antennas are designed using an in situ optimization approach based on a genetic algorithm. The layout of a pixelated metallic patch surrounding a monopole antenna is optimized such that tuning over a wide range of frequencies can be achieved by varying the capacitance of a varactor embedded in the structure.