Difference between revisions of "EM.Cube FAQ"

Revision as of 22:22, 15 October 2018

EM.Cube FAQ

What formulae are used while calculating the radiation patterns, and other parameters like gain, directivity

The Far-Field Approximation for Radiation & Scattering Problems at:

http://www.emagtech.com/wiki/index.php/The_Far-Field_Approximation_for_Radiation_%26_Scattering_Problems

what is meant by LCS settings?

EM.Cube provides a number of different coordinate systems. The two most important ones are the World Coordinate System (WCS) and the Local Coordinate System (LCS). Every object has a Local Coordinate System that determines the location of the object in the world coordinate system and its orientation, i.e., its rotation angles with respect to the world principal axes. The center of the local coordinate system is the most important characteristic point of an object. The position of the LCS center varies among different object types. For example, the LCS center of a box is the center of its bottom face, while the LCS center of a sphere is its true geometrical center. The LCS has three local X-, Y-, and Z-axes. For most objects, these axes line up with the object's natural axes. For example, the local Z-axis of a cylinder or a cone is always aligned along its geometrical axis. For further information please see the "Local Coordinate System" section at:

http://www.emagtech.com/wiki/index.php/Building_Geometrical_Constructions_in_CubeCAD#Local_Coordinate_System

How can we include different materials/metals and their properties in predefined arrays?

For simplicity, in our tutorials we use wizards to create antenna for a project. However, one can starts project from scratch and include different materials/metals with their properties in their design and then use the "Array Tool" from the tool bar to create an array. We may not need to use wizards for a complicated design.

How do we change the element spacing in line arrays?

If you start your project from scratch and use "Array Tool" to create say a 3 x 3 array with 5 mm spacing, simply set Element Count for X, Y and Z to 3, 3 and 1 respectively, and Spacing to 5, 5, and 0 for X, Y, and Z respectively, in Array Properties dialog window as indicated in the attached figure.

However, if you use a wizard, the Spacing might be parameterized in terms of other variables. For instance, in EM.Libera's Tutorial Lesson 2, In in Array Properties dialog window the Element Count for X, is expressed as direct_spacing_lambda and X Spacing is defined in terms of n_direct. To change X Element Count = 50 and X Spacing = 7 you may simply replace n_direct with 7 and direct_spacing_lambda with 50.

Alternatively, it is suggested, to keep n_direct and direct_spacing_lambda in the Array Properties dialog window untouched, yet, change their values from the Variables dialog window.

What is a good way to draw a surface with a curve of y0 * exp(r*x) where I can run a parametric study of r? Again drawing parametric curves and then fill fixed the design.

You can use "Taper Strip Tool" and check mark the "Exponential" check box.

http://www.emagtech.com/wiki/index.php/Glossary_of_EM.Cube%27s_Standard_Geometric_Objects#Taper_Strip_Tool

I have been using EMCUBE on my new workstation. I just realized that the wizards (e.g., the wire dipole wizard) are not active. If I remember correctly, I faced this issue previously and it was because one of the folders were missing (the folder with the python based wizards I think). I don't have that folder anymore.

. There are few updates that were not included in the link EMCUBEfiles.zip we sent you on February. Therefore, we include them in EMCubeNewWiz.zip file that can download it from the following link:

http://www.emagtech.com/downloads/EMCubeNewWiz.zip

1. Please Unzip EMCubeNewWiz.zip file. It contains three folders Models, Python, and Wizards. 2. Copy or move the new Models, Python, and Wizards into C:\Users\username\Documents\EMAG folder let it overwrite the existing ones.

Kaz has mentioned that you have problem with plot function while trying to plot for the second time. You cannot have more than one PyPlot graph window open at one time. For this reason an error window pops up indicating "Another PyPlot window ... is already open. Please close ..." In other words, you have to close the 1st PyPlot graph window before plotting another graph or running the simulation.

Nonetheless, sometimes the PyPlot window will buried or concealed under other windows. Please make sure to bring the PyPlot window up/front and close it before plotting another data set.

The advantage of using PyPlot is that allows you to plot two data set files (with same type, e.g. .CPX) in the same PyPlot graph window as shown in the attached figure. You can have two instances of EM.Cube program and each have independent PyPlot graph windows.

I read from your website that your software can determine k-beta diagram of periodic structures which is commonly called DISPERSION DIAGRAM. Do you have any model for that purpose? I searched periodic structures and could not find any model.

To determine k-beta diagram of periodic structures, you can follow our EM.Tempo Tutorial Lesson 8: Analyzing A Periodic Frequency Selective Surface:

http://www.emagtech.com/wiki/index.php/EM.Tempo_Tutorial_Lesson_8:_Analyzing_A_Periodic_Frequency_Selective_Surface

and select "Dispersion Sweep" from the Run Simulation window as indicated in the attached figures (KBT1a.png and KBT1b.png). Attached please also find a sample project (KBT1.zip). Please unzip KBT1.zip and run the simulation. You may plot "despersion_sweep_reflection.DAT" and "despersion_sweep_transmission.DAT" from the Data Manager.

How can I import my own radiation patterns in Terrano *.rad where I have for each antenna in the transmitter and receiver both the co-polarized and cross-polarized radiation patterns? Also, do you have the manual of Terrano?

. To import a radiation patterns (*.rad) in EM.Terrano open the property dialog of the transmitter set (or receiver set) and select the radio button labeled User Defined Antenna Pattern as the radiator type. Then click the Import button of the dialog. The Windows standard Open dialog opens up with the file type set to ".RAD". Browse your folders to find the downloaded pattern file. Select it and click the Open button. You will see the path of the downloaded file in the box next to the Import button.

Please see the Importing External Antenna Radiation Patterns for the Transmitter & Receivers section in EM.Terrano Tutorial Lesson 8: Simulating A Communications Link With Directional Antennas: http://www.emagtech.com/wiki/index.php/EM.Terrano_Tutorial_Lesson_8:_Simulating_A_Communications_Link_With_Directional_Antennas#Importing_External_Antenna_Radiation_Patterns_for_the_Transmitter_.26_Receivers You can view EM.Terrano Manual from the following link: http://www.emagtech.com/wiki/index.php/EM.Terrano

All information on EM.Cube can be found from EM.Cube Wiki page http://www.emagtech.com/wiki/index.php/EM.Cube