Cloak (Metamaterial)
 
A plane wave will have no reflection when it passes a cloaking structure. GEMS is used to simulate both the normal and oblique incidence cases.
 
The basic design procedure in the simulation:
Draw an inner cylinder
Draw an open ring
Generate an array using the open ring on the cylindrical surface
Design the excitation pulse
Set the domain size and boundary with a proper boundary condition
Generate the adaptive mesh
Set the incidence plane wave
Specify the convergence criterion
Simulate the project using PC or cluster
The basic settings in the simulation:
Option
Setting
Description
BoundaryXMin: PEC; XMax: PML; YMin: PML; YMax: PML; ZMin: PMC; ZMax: PMC  Only simulate the half of the original problem using PEC and PMC boundary
Plane wave

Incident angle:
Phi=270 deg.; theta=90/135 deg.
Polarization: Ex

The polarization should match the boundary
MeshFine mesh inside the cloak structureFine mesh to describe the open ring structure
OutputTime domain field distribution in the x-y and y-z planesTo view the field behavior through the cloak structure 
SimulationPC or ClusterA single PC can simulate the normal incidence case, and a 4/8-node cluster can simulate the oblique incidence case
 

Cloaking Structure Configuration

Normal Incidence Plane Wave

Oblique Incidence Plane Wave
Field Behavior Through Cloaking Structure (normal incidence)
Field Behavior Through Cloaking Structure (Obilque incidence)