4.3     Media

The  button in Model tab and Parameters->Media... command from main menu invoke Project Media dialogue.

Each of the projects has its own list of media. The list of the current project media is displayed on the right hand side of the dialogue window. On the left hand side a media editor is available. Here we can edit (by default) current project media or media from media libraries, in which we can store the parameters of media for all our projects. These libraries are saved to the *.mlb on the disk. We can pick one of them by pressing Load… button, which becomes so called active library.

Note that a standard installation of QuickWave contains four media libraries: standard.mlb, standard_with_food.mlb, default.mlb, and tissues2450_IFAC_CNR_Florence_IT_1997.mlb.

The tissues2450_IFAC_CNR_Florence_IT_1997.mlb library has been created based on:

D. Andreuccetti, R. Fossi, and C. Petrucci: An Internet resource for the calculation of the dielectric properties of body tissues in the frequency range 10 Hz – 100 GHz. IFAC-CNR, Florence (Italy), 1997. Based on data published by C. Gabriel et al. in 1996. Available online at: http://niremf.ifac.cnr.it/tissprop/

The name of the active library appears in the header of the window. One medium from this library is selected and its name and parameters are displayed in the dialogue. From the Name list we can select any other medium to display its parameters. These parameters can be modified.

Each non-dispersive medium can have up to eighteen parameters. Twelve of them describe its electromagnetic properties: permittivity, permeability, conductivity and magnetic losses along the three main axes of the coordinate system. Dispersive media have additional parameters describing the dispersion model or models.

There are also six thermal parameters. Specific heat, initial temperature, and thermal conductivity are relevant only if the QW-3D package operates with the optional QW‑BHM module (thermal conductivity is relevant for QW-HFM module). Density is used in QW-BHM, and also for calculating Specific Absorption Rate (SAR).

Note the following meaning of abbreviations used in the Project Media dialogue:

·       Eps = e_r [dimensionless]

·       Mu  = m _r [dimensionless]

·       Sigma = s [S/m]

·       SigmaM = s_m/(k)⁴ = wm₀m_r“/(k)⁴ » wm₀m_r“/(120*π)²  [W/m], k = (μ₀/ε₀) ^0.25 » (120 p)^0.5

·       Density = r [g/cm³]

·       Specific heat [J/(g°C)]

·       Initial temp. [°C]

·       Thermal conductivity= Kx, Ky, Kz [W/cm°C]

Parameters of the media can be modified. To the right from the media parameters table we have three additional commands concerning modification of the medium:

·       Insert to clear the current medium display waiting for a new one to be introduced

·       Delete to delete the current medium

·       Next to pick up next medium from the active library list

Another group of commands concerns operation on libraries. In the lower part of the dialogue window we have three commands:

·       New for creating a new library

·       Load for loading another library from a disk as an active library

·       Save for saving the active library

Finally, we can see the Pen and Brush commands, which are used to assign colours to media. They affect the QW-Editor and QW-Simulator displays as follows:

·       when an element made of a certain medium is drawn manually, Pen assigned to the medium determines the colour for displaying this element. However, subsequent changes of the medium assigned to this element are not automatically reflected in the changes of colour.

·       when external object is drawn in QW-Editor using UDO Library, Pen assigned to the medium determines the colour for displaying elements composed of this medium and included in the external object.

·       when TestMesh operation is performed in QW-Simulator, each homogeneous subregion is displayed as determined by Brush of the medium, and meshing over this subregion is drawn in Pen.

The Chart button is available for Dielectric dispersive, Metamaterial, Dielectric dispersive nonlinear and Cold Plasma materials and invokes Dispersive Media Chart with dispersive characteristics for the specified frequency range.

One of typical operations performed in the Project Media dialogue window is adding a particular medium to the project. To do this we select a medium from the active library and press -> button to move it to the project list.

While openning Project Media dialogue window, project media are automatically moved to the media editor on the left side. If on the left side active library is edited and we wish to update some media involved in the project without modifying the libraries, just press <-<-<- button. We see that the whole list of project media has replaced the current active library on the left hand side of the dialogue window. At the same time the window header has changed indicating that now, instead of the active library, we are dealing with the project media list. We can modify, delete or add media on that list. After the operation is over move the updated list back to the right hand side of the window. We can see that the button -> has changed to ->->->. This means that now by pressing this button we will move to the project media list, not just one item but the entire updated list. The ->->-> operation includes saving of the updated project media list.

The following media types are supported byQuickWave:

·       PEC

·       PMC

·       Metallic

·       Dielectric isotropic

·       Dielectric anisotropic

·       Dielectric dispersive

·       Dielectric dispersive anisotropic

·       Dielectric dispersive nonlinear

·       Cold Plasma

·       Metamaterial

·       Ferrite