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EM.Cube FAQ

5,060 bytes added, 13:58, 26 August 2022
== EM.Cube FAQ ==
 
Questions/Answers
What formulae are used while calculating the radiation patterns, and other parameters like gain, directivity
All information on [[EM.Cube]] can be found from [[EM.Cube]] Wiki page
http://www.emagtech.com/wiki/index.php/EM.Cube
 
 
1. Picasso: Is it possible to define Vias that go through more than one layer ?
 
You can define Vias' for each layer in such a way that they are positioned/located on top of one another and are exactly the same.
 
2. Why loss tangent is not automatically specified for known commercial materials, e.g. RO4003C ?
 
Thank you for bringing it into our attention. We will add it in the next released version.
 
3. Is it possible to Copy and object together with rotation/mirror ?
 
Mirror operation keeps the original object and create a new one. Yet, in rotation the original object will change. For this reason you may copy and the rotate the copied object.
 
4. Can [[EM.Cube|EM-cube]] support metal surface roughness (this is crucial for high microwave applications) ?
 
We do not have a parameter for the surface roughness in [[EM.Picasso]]. However, there is a relation between the surface roughness and the effective conductivity. You can use "Conductive Sheet Traces" with the effective conductivity. and rms height instead of "PEC Traces". We will add this option in the next release.
 
1) How do I write the Python Code for my own objects and add it to the simulation? Is it possible to access some part of the code for reference?
 
The following link provide an example how to write a Python script
 
http://www.emagtech.com/wiki/index.php/EM.Tempo_Tutorial_Lesson_7:_Designing_A_Pyramidal_Horn_Antenna#Writing_a_Python_Script_for_Calculation_of_Pyramidal_Horn_Directivity
 
Here is a more detailed information on [[Using Python to Create Functions, Models & Scripts]]
 
http://www.emagtech.com/wiki/index.php/Using_Python_to_Create_Functions,_Models_%26_Scripts
 
2) For modelling of wired antennas, I have used thin wires for respective elements. How will I consider the geometry of a thin wire for calculating current densities in each element? Also, do I have to take only thin wires or while modelling wired antennas or will cylindrical structures do?
 
In [[EM.Libera]], if you open up he Thin Wire dialog, in the property dialog, you can change the define the wire radius from "Wire Radius" box. In other words, it’s a tiny cylinder with small radius of "Wire Radius."
 
Please see "Constructing the Wire Dipole Antenna Geometry" section in the [[EM.Libera Tutorial Lesson 1: Analyzing A Center-Fed Wire Dipole Antenna]]
 
http://www.emagtech.com/wiki/index.php/EM.Libera_Tutorial_Lesson_1:_Analyzing_A_Center-Fed_Wire_Dipole_Antenna#Constructing_the_Wire_Dipole_Antenna_Geometry
 
3) What exactly is the function of a 'Port Definition'? How is it used in calculating the antenna parameters?
 
Ports are defined to calculate the scattering, impedance and admittance parameters of a one-port or multiport structure.
 
Port Definition Observable
 
http://www.emagtech.com/wiki/index.php/Glossary_of_EM.Cube%27s_Simulation_Observables_%26_Graph_Types#Port_Definition_Observable
 
Graphing Port Characteristics & Other Complex-Valued Data
 
http://www.emagtech.com/wiki/index.php/Defining_Project_Observables_%26_Visualizing_Output_Data#Graphing_Port_Characteristics_.26_Other_Complex-Valued_Data
 
4) How do I use the 'Wire gap circuit source' in between two thin wires? If it is not possible, is there any other method of excitation?
 
A wire gap source must always be associated with an existing line object in the project workspace. Please note that when you define your line object say 150 mm, the wire gap source creates an infinitesimal gap on the line, i.e. create two lines of 75 mm length, and connects a voltage source across the gap. All happens behind the scene. Please look at Examining the Gap Source & Simulation Observables in Lesson 1
 
http://www.emagtech.com/wiki/index.php/EM.Libera_Tutorial_Lesson_1:_Analyzing_A_Center-Fed_Wire_Dipole_Antenna#Examining_the_Gap_Source_.26_Simulation_Observables
 
 
1. How do i set simultaneous excitation of multiple ports ?
2. Can i use amplitude of -1 in order to create a 180 phase shift between ports in the FDTD simulation ?
otherwise, how can i stimulate 2 ports with 180 degrees phase shift ?
3. Can i choose some ports to be stimulated and others with no stimulation (just as a termination) ?
 
 
You can define multiple sources that will set the corresponding ports. In [[EM.Cube]] amplitude of the source should not be negative. For this reason, in order to introduce phase shift of 180 deg., you can click on "Waveform..." button in the "Source Properties" section of a Source dialog window. In the "Excitation Waveform" dialog window, set the Amplitude to 1 and the Phase to 180. Similarly, by setting the Amplitudes of some sources to 0 (zero) you can let some ports to be stimulated while those with zero amplitude without any stimulation (terminated).
 
To calculate S11-S12, you can do post-processing by getting them into Python. You can perform some operations (add, subtraction ...) on RCSs, Radiation Patterns, Field Sensors, etc. Yet, we do not have any Python function for S-parameter operations. We will implement some new Python in the next [[EM.Cube]] release.
Asabet
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