The AN-SOF Calculation Engine

The AN-SOF calculation engine is a high-performance electromagnetic solver written in C++ using double-precision arithmetic. It has been specifically developed to overcome the limitations of traditional wire-antenna modeling and to provide superior accuracy for complex metallic structures.

Conformal Method of Moments (CMoM)

At its core, the engine solves the Electric Field Integral Equation (EFIE) in the frequency domain. While standard solvers utilize the traditional Method of Moments (MoM) with straight-wire approximations, AN-SOF employs the Conformal Method of Moments (CMoM).

In this approach, curved wires are modeled using conformal segments that exactly follow the physical contour of the structure. Traditional linear approximations are often inefficient, requiring a high number of unknowns and excessive computer memory to represent a curve. By using curved segments, AN-SOF significantly reduces the number of unknown currents, simulation time, and memory overhead, allowing for the analysis of much larger and more complex problems.

Overcoming Legacy MoM Limitations

Many legacy MoM codes, especially those based on the thin-wire kernel and linear geometry approximations, suffer from several critical drawbacks that AN-SOF is designed to eliminate:

• Impedance Divergence: Traditional codes often produce divergent input impedances as segment density increases.
• Poor Convergence for Curved Structures: Helices, loops, and spirals are often poorly represented by straight-wire segments, leading to inaccurate results.
• Proximity Singularities: Numerical errors frequently occur when two parallel wires are in close proximity or when a wire is near a lossy ground plane.

Exact Kernel Formulation

By combining CMoM with an exact kernel formulation, AN-SOF removes the reliance on the “thin-wire approximation.” This provides several distinct advantages for the user:

1. Enhanced Accuracy: The precision of current distribution and far-field calculations is significantly increased.
2. Resource Efficiency: Lower memory usage and faster computation times facilitate the modeling of larger designs on standard hardware.
3. Broad Frequency Range: The engine maintains stability across an extreme spectrum, from very low frequencies (60 Hz power circuits) to high-frequency microwave applications.