Sphere

The Sphere Command

The Sphere command allows you to create spherical conductive structures, which are useful for modeling satellite bodies, spherical antennas, scattering targets (RCS studies), or spherical ground systems.

To open the tool, navigate to Draw > Wire Grid / Solid Surface > Sphere.

Defining the Geometry

In the Sphere tab, you configure the physical dimensions and orientation of the sphere using these parameters:

• Center Coordinates (Cx, Cy, Cz): The exact origin point of the sphere.
• Radius: The distance from the center to the surface.
• Orientation (Theta and Phi): While a perfect sphere is symmetrical, these angles define the orientation of the poles (the axis of the azimuthal and polar facets). This is important when you need to align the sphere’s mesh with other connected wires.

Curvature Options

• Curved Segments: This provides an exact mathematical representation of the sphere’s curvature. It is the preferred setting for high-frequency simulations to ensure smooth current flow and accurate scattering results.
• Straight Segments: Approximates the sphere using a series of flat facets made of linear wires, resulting in a polyhedral shape (similar to a geodesic dome).

Faceting and Mesh Attributes

In the Attributes tab, you define the computational density of the sphere:

• Facets: Specify the number of divisions along the Polar (latitude) and Azimuthal (longitude) directions.
• Wire Grid: Select Circular cross-section to create a transparent mesh, often used for “caged” or wire-frame spherical reflectors.
• Solid Surface: Select Flat or Rectangular cross-sections. AN-SOF will automatically calculate the tapering strip widths to ensure the spherical surface is completely covered without gaps.

Materials

The Materials tab allows you to set the resistivity of the sphere (e.g., Silver, Copper, or Aluminum) and to add any optional dielectric coating or insulation.