SATCOM Radome Power Control for Poor Axial Ratio Zones
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Solution Overview
Problem
Poor axial ratio performance in satellite communications due to the aerodynamic nature of radomes on vehicles, leading to interference with other terminals and blockage areas where communication is not possible.
Innovation Solution
A method and system that utilize a map of power spectral density limits by azimuth-elevation pair to control the operation of satellite communication networks, adjusting power levels, symbol rates, and chip rates to maintain communication within regulatory limits, using Open Antenna to Modem Interface Protocol (Open-AMIP).
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If aerodynamic radomes are used on vehicles, then the radome provides necessary aerodynamic protection, but poor axial ratio performance occurs in certain areas leading to communication blockage
Solution Approach 1:
The patent applies local quality by creating a non-uniform reflector surface with varying curvature and orientation across different regions. The reflector is designed with specific local geometric properties (different radii of curvature, tilt angles) in different zones to compensate for the aerodynamic radome's distortion effects at each location, thereby maintaining consistent axial ratio performance across the entire aperture.
Solution Approach 2:
The patent employs asymmetry by designing a reflector surface that is intentionally non-symmetric and non-uniform. Rather than using a conventional symmetric parabolic shape, the reflector features varying curvature and orientation that asymmetrically compensate for the aerodynamic radome's shape, transforming the distorted wavefront into a properly focused beam with maintained polarization characteristics.
2Object-affected harmful factors
If transmission is ceased in poor axial ratio areas, then interference with other terminals is avoided, but blockage areas are created where terminal cannot operate
Solution Approach 1:
The patent converts the harmful effect of the aerodynamic radome's distorted wavefront into a benefit by using a specifically designed reflector surface. The reflector takes the distorted signal passing through the radome and uses controlled reflection with varying local orientations to correct the phase and amplitude distribution, transforming the distorted wavefront into a properly focused beam that maintains acceptable axial ratio and minimizes interference while preserving communication capability.
3Device complexity
If conventional reflectors are used with aerodynamic radomes, then the system is simple in design, but axial ratio performance degrades in certain flight routes
Solution Approach 1:
The patent applies dynamics by designing a reflector surface with continuously varying local properties rather than a static uniform geometry. The reflector's surface orientation, curvature radius, and slope angle dynamically change across different spatial locations to adaptively compensate for the radome's distortion effects at each point, maintaining consistent performance across varying flight conditions and satellite positions.
Data Source
AI summary
A method, apparatus, system and computer program product are provided for controlling satellite communication in a satellite communication network during movement of a vehicle comprising one or more antenna elements. Radomes for airborne Satellite Communications (SATCOM) terminals have areas of poor axial ratio (also known as cross-polarization discrimination) due to the aerodynamic nature of the radome. Rather than turning off the power when passing through certain regions, a power spectral density limit is provided to the modem based on an azimuth angle and an elevation angle of the antenna. The power spectral densities may be accessed in a map by azimuth-elevation pairs and are dependent upon axial ratio limits of the satellite communication network. The map corresponds to a shape of the radome, or a physical characteristic of the vehicle.