Band-Selective Aperture Shading for Phased Array Sidelobe Reduction
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Solution Overview
Problem
Mobile satellite terminals face challenges with mechanical steering systems being bulky and expensive, and existing phased array antennas struggle to meet regulatory sidelobe requirements for satellite communications, necessitating a solution for efficient beam shaping and power distribution.
Innovation Solution
The implementation of band-selective phased array aperture shading using a system with planar array antenna tiles and unequal power distribution through feed network elements, such as PCB traces, to achieve customized power levels across patch antenna elements, allowing for tailored shading patterns that reduce sidelobes while maintaining high sensitivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If mechanical steering systems are used in reflector antennas, then the antenna can be aimed at desired satellites, but the system becomes bulky and expensive
Solution Approach 1:
The patent replaces mechanical steering systems with electronic beam steering using phased array technology. Multiple antenna elements are controlled with different phase shifts to electronically steer the beam without mechanical movement, eliminating bulky mechanical components while maintaining satellite aiming capability
Solution Approach 2:
The antenna system is divided into multiple discrete antenna elements arranged in an array. Each element can be independently controlled with individual phase shifters, allowing electronic beam steering through coordinated phase control of segmented elements rather than mechanical movement of a single reflector
2Ease of manufacture
If uniform power distribution is used across all antenna elements, then the antenna structure is simple, but regulatory sidelobe requirements cannot be met
Solution Approach 1:
The patent applies different amplitude weights to different antenna elements based on their position in the array. Edge and corner elements receive lower power levels than interior elements, creating a tapered illumination pattern that reduces sidelobe levels while maintaining main beam performance, thus meeting regulatory requirements
Solution Approach 2:
The feed network incorporates variable gain amplifiers or attenuators that can dynamically adjust the power distribution to each antenna element. This allows the system to adapt the amplitude tapering level as needed to meet varying sidelobe requirements while maintaining the ability to use uniform distribution when appropriate
3Object-affected harmful factors
If aperture shading is applied to reduce sidelobes, then regulatory requirements are met, but receive sensitivity may be compromised
Solution Approach 1:
The patent employs independent phase shifters and variable gain amplifiers for each antenna element, allowing dynamic adjustment of amplitude and phase. This enables the system to optimize the aperture shading pattern in real-time to meet sidelobe requirements while minimizing impact on receive sensitivity through adaptive control
Solution Approach 2:
The system changes the operational parameters of each antenna element individually, specifically the amplitude weight and phase shift, to achieve the desired shading pattern. By precisely controlling these parameters, the system can reduce sidelobes while maintaining optimal receive performance through optimized weight distributions
Data Source
AI summary
For phased array aperture shading for sidelobe reduction in satellite communication transceivers, apparatus and systems are disclosed. One apparatus includes a planar array antenna tile having a plurality of patch antenna elements. The apparatus also includes a transmit feed point that drives the planar array antenna tile. The apparatus further includes a feed network element that distributes power unequally among two or more of the patch antenna elements, wherein the feed network element connects the two or more patch antenna elements to the transmit feed point.