Conformal Electro-Textile EBG Ground Plane for GPS Antenna Back Radiation
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Solution Overview
Problem
GPS antennas on aircraft suffer from significant back radiation due to 'creeping waves' caused by curved surface diffraction, making them vulnerable to interference from ground-based sources, and existing broadband ground planes are inflexible, heavy, and unsuitable for curved fuselage shapes.
Innovation Solution
A Reduced Surface Wave (RSW) antenna is placed on a conformal Electronic Band Gap (EBG) ground plane made from electro-textiles, which suppresses back radiation by using a combination of conducting, non-conducting, and resistive textiles to widen frequency response and attenuate creeping waves, allowing the system to be flexible and adaptable to aircraft shapes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If conventional broadband ground planes are used to suppress back radiation, then radiation suppression is improved, but flexibility and adaptability to curved surfaces deteriorate
Solution Approach 1:
The patent applies flexible electro-textile ground planes that can conform to curved aircraft fuselage surfaces. These textile-based ground planes replace rigid conventional ground planes, enabling adaptation to curved surfaces while maintaining electromagnetic shielding functionality to suppress back radiation from GPS antennas.
Solution Approach 2:
The patent uses composite electro-textile structures combining conductive fibers, dielectric layers, and resistive materials to create ground planes that simultaneously provide electromagnetic shielding, flexibility, and conformability to curved surfaces. The composite structure integrates multiple material properties to resolve the contradiction between radiation suppression and surface adaptability.
2Weight of moving object
If microstrip patch antennas are used on aircraft, then aerodynamic drag is reduced, but creeping wave generation increases
Solution Approach 1:
The patent converts the harmful creeping waves generated by microstrip patch antennas into a controlled phenomenon by placing the antennas on curved fuselage surfaces. The curvature of the fuselage naturally diffracts and reduces the propagation of creeping waves, transforming the low-profile advantage of microstrip antennas into a configuration that minimizes their harmful electromagnetic effects.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The RSW antenna and EBG ground plane significantly reduce back radiation, improving GPS signal integrity by minimizing interference from ground-based sources and enabling operation across multiple GPS frequency bands, including L1, L2, and L5, while being lightweight and flexible for installation on curved aircraft surfaces.
Implementation Method 1
Electronic Band Gap (EBG) ground plane that is conformal to the fuselage of the aircraft... attenuate creeping waves
Implementation Method 2
This radiation is primarily caused by what is known as 'creeping waves' generated by curved surface diffraction
Data Source
AI summary
An antenna system having reduced back radiation is disclosed. The antenna system includes an antenna and ground plane. The antenna includes electro-textiles and is configured to operate in at least the frequency range between 1.1-1.6 GHz. The ground plane includes electro-textiles and is configured to operate as a frequency selective surface with electronic band gap characteristics to suppress edge and curved surface diffraction effects. In this system, the antenna and ground plane are configured to be located on a curved surface and to radiate with a directional radiation pattern having attenuated back lobes.