Crossed Dipole Antenna Low Elevation Gain via Conductive Posts
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Solution Overview
Problem
Aeronautical satellite communications systems experience reduced gain and connectivity at low elevation angles due to the poor performance of aircraft antenna systems, particularly at northern or southern latitudes, leading to low throughput and loss of connectivity at the edges of the satellite footprint.
Innovation Solution
The antenna system incorporates conductive posts as coupling devices, which are oriented orthogonally to a printed circuit board and connected via solder joints to a ground plane layer, enhancing gain at low elevations by coupling driven radiator elements, such as crossed-dipole antennas, with displacer material providing mechanical stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If a low profile circularly polarized antenna is used on top of a fuselage, then the antenna structure is compact and suitable for aircraft installation, but the gain towards the horizon is low
Solution Approach 1:
The patent introduces vertical conductive posts extending from the ground plane to interact with the circularly polarized antenna elements. These posts create a three-dimensional structure that modifies the radiation pattern, specifically enhancing gain in the horizontal direction (low elevation angles) while maintaining the low-profile characteristic of the overall antenna system.
Solution Approach 2:
The patent modifies the antenna system by adding conductive posts with specific dimensions (height, diameter, spacing) to change the electrical parameters of the antenna. The posts are positioned at specific distances from the antenna elements and have controlled impedances that transform the radiation characteristics to improve low-elevation gain without significantly increasing the overall profile height.
2Adaptability or versatility
If omnidirectional antennas or phased array designs are used, then coverage is improved, but gain at low elevation angles remains poor at northern or southern latitudes
Solution Approach 1:
The patent introduces asymmetric vertical conductive posts that break the symmetry of the circularly polarized antenna system. This asymmetry is deliberately designed to create directional radiation enhancement towards the horizon while maintaining omnidirectional coverage in the horizontal plane. The posts are positioned and dimensioned to create different electrical lengths and impedances that favor low-elevation radiation.
Data Source
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AI summary
An antenna system is provided that includes at least one driven radiator element and at least one coupling device. The at least one driven radiator element is disposed above a printed circuit board. The at least one coupling device has a step feature in at least one of width and diameter. A smaller of the at least one of the width and diameter is received in at least one of a via and slot in the printed circuit board. The at least one coupling device is oriented nominally orthogonal to a plane of the printed circuit board. The at least one solder joint couples the at least one coupling device to the printed circuit board. At least one ground plane layer is electrically connected to the at least one coupling device by at least one of the solder joint and the at least one of a via and a slot.