The following is only available in FDTD and MODE:
The helix and spiral objects can be found in the Object library Structures category under the "Uncategorized structures" heading. This section describes how these two types of spiral objects are created.
The spiral is created with a series of polygon primitives. In this example, each ring of the spiral is one polygon object.
The top figure above shows the spiral structure group object from usr_spiral.fsp. Spiral parameters such as radius, types of the two materials that make up the spiral, and number of turns can be modified by editing the user properties of the group.
The helix object is created with a series of thin cylinders. The second figure above shows a helix structure group object from usr_helix.fsp. Helix parameters such as radius and number of turns can be modified by editing the user properties of the group.
Note: Simulation times when using large numbers of primitives.
The simulation time is not affected by the number of primitives used to create the physical structures.
The meshing time (which occurs before the simulation begins) will increase with the number of primitives used. However, since the meshing time is normally much less than the simulation time, this will not have a significant effect on the total simulation time.
With the Helix structure group, user may change the start and end radius of the helix to make it like a cone. User may want to pay attention to the situation when the "fiber radius" is comparable to the "end radius" that makes the structure distorted. In that case, changing the fiber radius or other parameters may need to be considered.