﻿ Ground-Penetrating RadarExamples | Product | Murata Software Co., Ltd.

### General

• A ground-penetrating radar with an exponential TEM horn antenna is analyzed.

• How the electromagnetic waves transmitted from the transmitter are received at the receiver can be viewed by the output voltage and result field.

• By comparing the results with and without a foreign matter, how the received voltage detects the foreign matter is verified.

• Unless specified in the list below, the default conditions will be applied.

• Electromagnetic-transient analysis is available in an optional package.

### Analysis Space

 Item Setting Analysis Space 3D Model Unit m

### Analysis Condition

With this model, it is necessary to trace the propagation of electromagnetic waves by several wavelengths, and the analysis size becomes large. So the 1st-order elements are used to reduce calculation time.

 Item Setting Solver Electromagnetic analysis [Hertz] Analysis Type Transient analysis   Select Input at each port

 Tab Setting Item Setting Mesh General mesh size 0.05[m] Element Type 1st-Order Element Frequency-Dependent Meshing Select The conductor bodies thicker than the skin depth constitute the boundary condition Select Determine the reference frequency automatically from the input waveform Transient analysis Waveform Type Broadband Pulse   Minimum frequency: 0.5[Hz] Maximum frequency: 1.0[Hz] Finish time of calculation 2.0×10-8 [s] Output Field *1 Select Output Field   Output Interval for Field: 1

*1 If you want to reduce the result size, increase the Output Interval for Field or deselect Output Field.
If the fields are not output, only the table values are output.

### Model

The model consists of an exponential TEM horn antenna (Horn1 and Horn2), which is a transmitting and receiving antenna, a reflecting object (Reflector) with an electric wall which is intended to avoid noise due to direct wave reception and diffraction,

an air domain (Air), soil, and a conductive pipe (Pipe) as a foreign body.

### Body Attributes and Materials

 Body Number/Type Body Attribute Name Material Name 0, 1/Sheet Horn1 001_Al * 2, 3/Sheet Horn2 001_Al * 4/Solid Air 000_Air * 6/Solid Pipe 008_Cu (*) 10/Solid Soil Soil

* Available from the material DB

The material properties of Soil are set up as follows.

 Material Name Tab Properties Soil Permittivity Relative permittivity: 2.0 Conductivity Conductor   Conductivity: 1.0×10-3 [S/m]

### Boundary Condition

 Boundary Condition Name/Topology Tab Boundary Condition Type Setting Port1/Face Electric Port Reference Impedance: 50Ω   Integral Path: Set Path1 Port2/Face Electric Port Reference Impedance: 50Ω   Integral Path: Set Path1 Reflector/Face Electric Electric wall Outer Boundary Condition Electric Open boundary

### Results

The transient analysis result of the output voltage is shown by red line.

For comparison, the result of analysis without foreign body (WithoutPipe) is shown by black line. As the graph shows, the analysis with a foreign body has a large signal reception

at around 10ns. It indicates that the electromagnetic waves from the transmitting antenna (Port1) are reflected by the conductive pipe and propagate to the receiving antenna (Port2).

The figures below are electric field contours of the XY cross section. From these figures too, it can be viewed how the electromagnetic waves from the transmitting antenna are reflected by the conductive pipe and propagate to the receiving antenna.

For clear comparison, the maximum value of the electric field is fixed at 0.5[V/m] in the graphics setup.

 Time [s] Electric Field Contour 2ns 4ns 5ns 6ns 7ns 8ns 9ns 10ns

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