Frequency-Selective Surface Subreflector for Satellite Ground Terminal Signal Isolation
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Solution Overview
Problem
Traditional satellite ground terminals require expensive and heavy waveguide devices to separate uplink and downlink signals, which add weight and increase costs due to the need for precise machining, and compromise between signal gain and isolation.
Innovation Solution
A frequency-selective surface module acts as a frequency diplexer, separating signals within the optical path between the reflector and focal point of the satellite antenna, allowing independent optimization of transmit and receive communication paths without the need for these waveguide devices.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If waveguide devices are used to separate uplink and downlink signals, then signal separation is achieved, but weight and manufacturing cost increase
Solution Approach 1:
The patent replaces mechanical waveguide devices with a frequency-selective surface (FSS) that uses electromagnetic field properties to separate uplink and downlink signals. The FSS is a two-dimensional periodic structure that selectively transmits or reflects electromagnetic waves based on frequency, eliminating the need for heavy machined waveguide components while achieving the same signal separation function.
Solution Approach 2:
The invention changes the separation mechanism from physical/mechanical waveguide structures to frequency-based electromagnetic field interaction. By utilizing the different frequency characteristics of uplink and downlink signals, the FSS achieves signal separation through parameter (frequency) differentiation rather than mechanical structure, significantly reducing weight.
2Reliability
If waveguide devices are used to separate uplink and downlink signals, then signal separation is achieved, but manufacturing cost increases
Solution Approach 1:
The patent replaces expensive precision-machined waveguide devices with a frequency-selective surface that can be manufactured using standard PCB fabrication techniques or other conventional manufacturing processes. The FSS consists of periodic conductive patterns on a substrate that are much easier and less costly to produce than precision-machined metal waveguide components.
Solution Approach 2:
The invention employs a cost-effective FSS structure that can be manufactured using inexpensive materials and standard fabrication processes, replacing expensive precision-machined waveguide components. The FSS achieves the same functional requirement at a fraction of the manufacturing cost.
3Device complexity
If a single feed horn antenna is used for both uplink and downlink, then device complexity is reduced, but signal isolation deteriorates
Solution Approach 1:
The patent introduces a frequency-selective surface positioned between the feed horn and reflector that uses electromagnetic field properties to provide signal isolation. The FSS acts as a frequency-dependent filter that allows the single feed horn to handle both uplink and downlink signals while maintaining proper isolation through frequency-selective transmission and reflection, rather than requiring separate physical paths.
4Reliability
If waveguide devices are used for signal separation, then signal isolation is improved, but device complexity increases
Solution Approach 1:
The patent merges the signal separation function into a single frequency-selective surface component rather than requiring multiple separate waveguide devices. The FSS integrates frequency filtering, signal separation, and isolation functions into one element that is positioned in the optical path between the feed horn and reflector, simplifying the overall device architecture.
Solution Approach 2:
The invention replaces complex mechanical waveguide assemblies with a planar frequency-selective surface that achieves the same signal isolation function through electromagnetic field interaction. The FSS provides a more compact and less complex solution compared to traditional machined waveguide devices.
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
This solution eliminates the need for heavy and costly waveguide components, enabling better signal isolation and optimization of each communication path, reducing interference and operational costs while maintaining efficient satellite communication.
Implementation Method 1
A frequency-selective surface module including a frequency-selective surface placed within the optical path between the reflector and the focal point of the reflector
Implementation Method 2
The reflector dish focuses the downlink signal from the satellite to the feed horn of the transceiver module
Implementation Method 3
The reflector dish focuses the downlink signal from the satellite to the feed horn of the transceiver module
Implementation Method 4
For the uplink signal, the reflector dish transforms a spherical uplink signal radiated by the feed horn antenna of the transceiver module into a planar uplink signal for transmission to the satellite
Data Source
AI summary
A device and method are described for duplex satellite communication over a single satellite antenna. A satellite ground terminal may utilize a frequency-selective surface module including a frequency-selective surface as a subreflector acting as a frequency diplexer to separate signals received and/or transmitted by a first feed and a second feed of a satellite ground terminal, where each feed has a separate antenna horn. The frequency-selective surface module may be used in combination with a second subreflector such that a first feed and a second feed of the satellite ground terminal are implemented on the same side of the frequency-selective surface module.