Modeling a Center-driven Dipole with HFSS (version 11.1.3)
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 Geometry and setup  |  
Geometry: L= 1 m, 
a = 0.5 mm  
Excitation: Lumped Port, 50 
ohms  
Mesh operation: Maximum length of elements=50 mm 
Analysis Setup:  
- Solution Frequency: 300 MHz              
 
- Maximum Number of Passes: 50              
 
- Maximum ΔS: 0.01              
 
- Do Lambda Refinement: 0.5              
 
- Maximum Refinement Passes: 20%            
  
Sweep:  
- Sweep type: Interpolate              
 
- Frequency: 50 MHz - 400 MHz, Step Size = 5 
MHz 
  
  hfss_dipole.zip            
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 Simulation result  |  
Simulation Time: 3 
mins 47 secs 
Number of passes completed: 6 
Number of tetrahedra: 14073
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 Decisions the user must make that affect the 
accuracy of the result  |  
- Location of absorbing boundary: λ/4 
(at 300 MHz) away from the object              
 
- Source type: use lumped port              
 
- Maximum ΔS: default value = 0.02, this model=0.01              
 
- Do lambda refinement: default value=0.33, this model=0.5		  
 
- Mesh operation: restrict the maximum length of elements              
 
- Dipole material: perfect conductor 
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 Comments  |  
- What if we model the wire as a 
flat ribbon?
 
 
We can substitute a 2-mm wide flat ribbon 
for the 0.5-mm round wire. The results are nearly the same.  
More information 
...               
- Where was the absorbing boundary 
located?
 
 
In HFSS, radiation boundaries are used to simulate 
open problems that allow waves to radiate to the far field. The 
accuracy of the radiation approximation depends on the distance 
between the boundary and the radiation source. The radiation 
surface must be located at least one-quarter wavelength from the 
radiating source. It should usually also be at a distance greater 
than the maximum dimension of the source.  
 For this 
simulation, the solution frequency is 300 MHz (λ = 1 m). The 
radiation boundary is defined on a cylinder whose radius is 500 mm 
and height is 2000 mm.    |    | 
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 Screen shots 
  
Fig. 1. Simulation model  
  
Fig. 2. Simulation meshes  
 </> 
Fig. 3. Input impedance  
  
Fig. 4. Input impedance at the first 
resonant frequency   |    |