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apatch






Apatch™ is an antenna design and analysis tool that provides antenna simulation and
modeling by computing the radiation and receiving pattern of an antenna or antenna array installed in an operational environment. The APATCH tool can operate on highly realistic, complex, 3-D CAD models that are accurate representations of the actual operating environment. See photo

The computer model uses an efficient and high fidelity electromagnetic modeling approach that is based on the shooting and bouncing ray (SBR) technology that is similar to SAIC\'s Xpatch® technology. The SBR method launches thousands of rays from the antenna(s) and traces them through multiple bounces as they interact with 3D models that define the operating environment. As the rays interact with objects, they deposit currents on the 3-D operational environment according to physical optics (PO) principles. These currents are then integrated to generate the scattering contribution of the antenna\'s environment to produce the overall installed antenna radiation pattern.
Applications

Apatch can operate on highly realistic complex CAD models of the actual radiating environment, thereby ensuring a great degree of confidence in the simulation results. Typical applications of Apatch include the following:

* Aircraft mounted antennas
* Antennas for ground vehicles and installations
* Ship superstructure interactions
* Spacecraft with antennas and other structures
* Reflector antenna systems
* Impact of radomes: dielectric and Frequency Selective Surfaces (FSS)
* Antennas on automobiles, trucks, ships, buildings, and mobile handsets

Apatch aids engineers in evaluating the interplay between the effects of antenna placement, vehicle geometry, and the surrounding environment. Users of Apatch include government organizations and major aerospace firms.

Apatch is currently available for Sun Solaris 2.6 or 2.7 and Silicon Graphics (SGI) IRIX 6.5 or higher platforms. Minimum requirements for Sun and SGI Workstations are 256 MB RAM and 200 MB disk space.
Features

Observation Angles: Provides the user several ways of defining antenna pattern observation angles in the far-field: sector sweeps, pattern cuts, and both azimuthal (horizontal) and conical cuts on a great circle of the far-field sphere.

Pattern Re-centering: Treats antennas as pattern weighted point sources. This requires that the complex pattern weighting be phase centered at the location of the antenna.

Current Sources Antenna Class: Eliminates accuracy degradation when the radiating source is large and near enough to scattering structures such that its far-field radiation pattern will not be representative of the fields incident upon the scatterer. Apatch allows the antenna to be replaced with an equivalent set of current sources for improved accuracy.

Sub-Array Zoning: With large planar arrays, antenna prediction codes represent the antenna as a collimated beam. The most accurate approach is to treat each array element as a point source, but it can be computationally prohibitive. Apatch provides a more accurate and less computationally demanding solution to these two extremes through sub-array zoning. Apatch groups neighboring array elements and treats each group as a new point source element. This solution speeds the analysis without losing accuracy.

Key Word Input: With key word input, the input files are smaller, parameters can be presented in any order, and commenting can be as extensive or sparse as the user desires.
Benefits

Apatch is one of the only codes in the US that supports prediction of the realistic interaction of an antenna with its environment. This modeling capability also provides an invaluable aid in analyzing existing systems and allows the system designer to experiment with various antenna placements to quickly characterize the radiation and coupling performance, thus leading to optimized antennae location.

Because our software identifies potential problems with antenna placement prior to testing, expensive cut-and-try design methods can be eliminated, thus significantly reducing design and development cycle times