Multifilar Helical Antenna Phasing Ring Resonance
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Solution Overview
Problem
Existing dielectrically-loaded multifilar antennas for circularly polarized radiation above 200 MHz face challenges in achieving efficient phase progression and stability, particularly for satellite communication services like GPS and S-band services, where they struggle to maintain circular polarization and resonance across allocated frequency bands.
Innovation Solution
A dielectrically loaded multifilar antenna design featuring a solid dielectric substrate with a relative dielectric constant of at least 5, a phasing ring resonant at the operating frequency, and elongate conductive radiation elements coupled to the phasing ring, which provides phase progression and circular polarization characteristics, allowing for efficient operation across multiple frequency bands.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a dielectrically-loaded multifilar antenna is used for circularly polarized radiation above 200 MHz, then the antenna can provide omnidirectional radiation pattern, but it struggles to maintain stable circular polarization and resonance across frequency bands
Solution Approach 1:
The patent employs a phasing ring resonant at the operating frequency that dynamically adjusts phase progression to the radiating elements. This resonant phasing structure adapts to different frequency bands while maintaining stable circular polarization characteristics, resolving the contradiction between reliability across frequencies and adaptability to different bands
Solution Approach 2:
The antenna design changes the phasing mechanism parameter by using a resonant phasing ring instead of conventional feeding structures. This parameter change enables the antenna to maintain consistent circular polarization and resonance stability across multiple frequency bands, including GPS and S-band services
2Reliability
If conventional feeding structures are used in dielectrically-loaded multifilar antennas, then the structure is simple, but phase progression and circular polarization characteristics are not achieved efficiently
Solution Approach 1:
The patent introduces a phasing ring as an intermediary component between the feed nodes and the radiating elements. This resonant phasing ring efficiently provides the required phase progression to achieve circular polarization characteristics, resolving the contradiction between reliable circular polarization and structural simplicity
Solution Approach 2:
The phasing ring serves multiple functions simultaneously: it provides phase progression, maintains resonance, and enables circular polarization across different frequency bands. This multi-functionality achieves reliable circular polarization characteristics while managing the inherent structural complexity through a unified design
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 antenna achieves stable circular polarization and resonance across the desired frequency range, enhancing its performance for satellite communication services by maintaining a low impedance and omnidirectional radiation pattern, suitable for both transmission and reception.
Implementation Method 1
a phasing ring formed by a closed loop which is resonant at the operating frequency, the radiating elements being coupled to the phasing ring at respective spaced apart coupling locations
Implementation Method 2
an electrically insulative substrate formed of a solid dielectric material having a relative dielectric constant of at least 5
Data Source
AI summary
In a dielectrically-loaded multifilar helical antenna, a conductive phasing ring is arranged between and couples together feed nodes and the helical radiating elements. The phasing ring includes an annular conductive path having an electrical length equivalent to a full wavelength at the operating frequency so as to be resonant at that frequency. The helical elements are coupled to the outer periphery of the phasing ring at respective spaced apart coupling locations. The helical elements may include open-circuit or closed-circuit elongate conductive tracks, or a combination of both. In the case of the helical elements being closed-circuit tracks, these tracks are interconnected by a second resonant ring, which is resonant at the same frequency as or a different frequency from the first resonant ring. The invention is applicable to both end-fire and back-fire helical antennas.