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

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

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

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

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.