This topic applies to the Eigenmode Expansion (EME) solver in MODE. For information on port objects in FDTD, see FDTD Ports.
The EME solver region contains 2 ports by default. The Ports button found in the main toolbar adds additional ports to the solver. Ports are labeled automatically and the port number corresponds to the terms in the calculated S-matrix result. You can change the port labels by changing the order that the ports are listed in the Objects Tree using the up and down arrows as shown in the image below.
- Port location: Allows users to automatically set the port location to the left or right side of the EME solver region.
- USE FULL SIMULATION SPAN: It uses the full simulation span inherent from the EME simulation region. By default this is option is on. Uncheck this option if users want to define their own spans for the port.
The following parameters will have no effects if USE FULL SIMULATION SPAN is checked. The value of the injection axis property set in the modal properties tab will control the available spatial settings below:
- X, Y, Z: The center position of the simulation region
- X MIN, X MAX: X min, X max position
- Y MIN, Y MAX: Y min, Y max position
- Z MIN, Z MAX: Z min, Z max position
- X SPAN, Y SPAN, Z SPAN: X, Y, Z span of the simulation region
- USE RELATIVE COORDINATE: Use coordinates relative to the parent object.
EME Port tab
- MODE SELECTION: Allows users to select the modes to use for the mode expansion calculation. The "user select" option launches the eigenmode solver where the user can calculate and visualize the supported modes (see Mode analysis); use this option to select multiple modes. The eigenmode solver also provides a tool for frequency analysis (see Frequency Analysis Tab).The "Mode calculation" section allows users to select a mode (or a set of modes) they are interested in. The user S-matrix result returns the S-matrix for these selected modes. A selected mode can also be used as an input source in the EME propagation stage of the analysis.
- SELECT MODE: If the "user select" option has been chosen, this will bring up the Mode analysis tab for the user to select from a calculated list of modes. Multiple modes can be selected at once.
- IMPORT FIELDS: Use a custom field profile from a .mat file. See importing arbitrary source fields for an example.
- VISUALIZE MODE DATA: This will bring up the Visualizer, showing all the profiles for the selected modes.
- CLEAR MODE DATA: Clears all the mode data.
- THETA: The angle of propagation, measured in degrees, with respect to the normal axis.
- PHI: The angle of propagation, in degrees, rotated about the normal axis in a right-hand context.
- NUMBER OF TRIAL MODES: The number of modes specified to look for in order to find a fundamental mode. This will affect the modes that the solver finds. If this number is too small, the desired modes may not be found. Often, setting this number to 100 modes will ensure that no physical modes have been missed. If more than 100 modes exist, then a larger number should be used if one is interested in higher order modes.
- OFFSET: Allows users to set an offset to the plane where the modes are calculated. This is useful for ensuring that monitors at an angle do not intersect with unwanted structures.
- NEFF: the effective index of the selected mode(s)
- MODE PROFILES: the spatial mode profile (E,H) of the selected mode(s)
- OVERLAP_FORWARD: Overlap between port mode and forward propagating modes of nearest cell.
- OVERLAP_BACKWARD: Overlap between port mode and backward propagating modes of nearest cell.
- PMATRIX: Power ( integrate(real(Px),1:2, y,z)) ) in the port mode, in Watts. When multiple modes are selected, it is the power overlap between each of the port modes. The diagonal of the matrix is the power in each mode. Typically the fields are scaled so this is about one watt.