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Where To Find This Example

AWR Version 14

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AWR Version 13

This example was renamed since the previous version. Please see Previous Example Page for the version 13 page.

Design Notes

Modeling Dipole_Antennas in MWO

Summary Information

1.   An Equivalent_Circuit representation is possible

2.   The 377 Ohm boundary conditions on the top and bottom surface should be used.

3.   The top/bottom enclosure boundaries heights should not matter since the boundary conditions are set to 377 Ohm. 

Simulation Results

The 3D antenna pattern for total power is shown in the 3D view of the EM Structure.  Double click on the annotation under the “Dipole_Antenna” EM document to see the options for this annotation.  

Equivalent_Circuit Approximation

The impedance of a thin dipole antenna is frequency dependent and should look like a circle, which is tangent to both an open and the 72 ohm point on the Smith chart. An equivalent circuit model would be a series tank circuit with R = 72 Ohms and the LC combination causing a resonance where the dipole is one half wavelength (Note this approximate model is only valid for near the 1/2 wavelength resonance). As the dipole gets physically wider (as is this simulation), the resistive portion should be lowered and the resonant frequency should be shifted down.

Optimization was used to find the equivalent circuit parameters.   The graph “Smodel” is plotting the error between the EM simulation results and the equivalent circuit model. The parameters of the equivalent circuit are setup to optimize in the “Equivalent_Circuit” schematic.  

EM Structure - Dipole_Antenna

EM Structure 3D - Dipole_Antenna

Graph - Antenna Patterns Principal Plane Cut

Graph - Antenna Patterns 90 Deg Conic Linear