Ground Penetrating radar
 
GEMS is used to simulate a GPR (Ground Penetrating Radar) model. A pair of broadband bow-tie antennas are used as the transmitting and receiving antennas. The soil is dispersive medium and the filled water inside the plastic pipe is the lossy material. GEMS is used to extract the time domain scattered signal reflected by the buried pipe.
 
The basic design procedure in the simulation:
Draw a pair of bow-tie antennas
Draw the excitation and output ports
Draw a box and define it as the soil with the Debye-type dispersive material
Draw a hollow cylinder and define it as a plastic pipe
Draw a cylinder inside the plastic pipe and define it as lossy material
Set the domain size and boundary
Generate the adaptive mesh
Specify the convergence criterion
Simulate the project using a single PC or cluster
The basic settings in the simulation:
Option
Setting
Description
BoundaryPML truncates all six walls

To simulate the infinite soil in the horizontal directions

Excitation

Lumped port

With 50 Ohms match load
MeshNon-uniform and conformal meshAdaptive mesh
OutputTime domain scattered signalYou need to run GEMS two times with and without the buried pipe
SimulationA PC or cluster 
 

GPR Model

 
Mesh and Material Distribution
Transmitting and Receiving
Antennas
 
Field Distribution in One Cross Section

Antenna Loads

 
Scattered Time Domain Signal
3-D Field Distribution