SIGLBC™

Overview

SIGLBC™ (3-Dimensional Signature Prediction/Radar Cross Section Analysis Code Using Moment-Method Approach) rigorously computes the RCS (Radar Cross Section) of systems/sub-systems and in-situ antenna patterns using generalized surface integral equations. SIGLBC has been developed with focus on the RCS designer. The formulation is selected to be robust in an environment of complex 3D shapes, optimization and fast incremental updates have been a paramount concern from the onset, and the code has been engineered for easy implementation on high speed platforms.

Applications

SIGLBC has been used successfully to analyze and design vehicle systems/sub-systems and integrated antenna systems requiring models having in excess 150,000 degrees-of-freedom. SIGLBC has been used to support a number of advanced vehicle design contracts. The principle use is to predict signatures of various vehicles such as aircraft, land vehicles, and ships. Once a baseline is developed, treatment concepts are optimized using various degrees of freedom to arrive at the best solution.

SIGLBC may be used for modeling antennas as well as target signatures. A unique feature of SIGLBC is that antenna patterns may be computed for antennas embedded in, or surrounded by, absorptive material treatments. In addition to patters, SIGLBC computes the complete mutual coupling impedance matrix. SIGLBC has been successfully employed for modeling micropatch antennas, cavity backed loaded slots, notch radiators, and several variants of monopoles and dipoles. These have been modeled as isolated elements (often on a groundplane) and in-situ on a weapon system. Input impedance computations have been used to optimize load impedances and to optimize the placement of elements (to minimize the degradation of patterns caused by mutual coupling). Gain calculations are often used for optimal integration of antenna elements with RAM treatments.

Benefits

• SIGLBC is the principal code using moment method for predicting and analyzing mono-static or bi-static radar cross section of 3-dimensional geometries. Besides RCS prediction, SIGLBC has the options to generate current maps and compute radiation patterns.
• SIGLBC is capable of handling large problem size by using out-of-core linear system solver. It is only limited by disk capacity.
• The optimizing feature of SIGLBC can compute a complete solution, change impedances of pre-selected facets and then compute the modified solution. This greatly reduces run-time to achieve optimum RCS results.

Product Features

• Accuracy
• Combined Field Formulation
• Analytic Singularity Extraction
• Gaussian Numerical Quadrature
• Matrix Pre-Conditioning
• Design Update Capability
• Efficient Incremental Solutions for Non-Linear Design Changers or Parametric Studies
• Analytic Solutions for Linear Perturbations
• Large Problem Size Capability
• Out-Of-Core Linear System Solver
• Problem Size Limited Only By Disk Capacity
• Internal Memory Management
• Efficient I/O
• Allows shunts, perfect electric conductors, impedance boundaries, and bulk materials, with or without the presence of an infinite perfectly conducting groundplane
• Complex shunt impedance film
• Complex & anisotropic IBC impedances
• No required volume modeling
• Groundplane may have apertures of arbitrary surface impedance
• Surfaces may be modeled below the groundplane
• Exploits bilaterally symmetric geometry
• Arbitrary 3-dimensional geometry w/ N-way junctions
• Generates diagnostic current maps
• Post processing current maps to produce antenna gain and mutual impedance matrix