Nested Helical Antenna System for Multi-Band GNSS and UHF
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Solution Overview
Problem
Conventional quadrifilar helical antennas (QHAs) have limited frequency bandwidth, making them inadequate for modern Global Navigation Satellite System (GNSS) systems that use multiple frequency bands, including Iridium and UHF communications, as they often operate at only one or two GNSS frequency bands.
Innovation Solution
A multi-use antenna system is developed, featuring a first antenna with radiating elements wrapped around a dielectric or foam rod, including capacitance coupling between driven and folded arms, and a second antenna co-located within the first, sharing a common ground plane to enhance bandwidth and operational frequency range, covering GNSS, Iridium, and UHF bands.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a conventional quadrifilar helical antenna is used, then the antenna provides right-hand circularly polarized gain from zenith to horizon, but the frequency bandwidth is limited to one or two GNSS bands
Solution Approach 1:
A second antenna is nested within the first antenna structure. The second antenna includes radiating elements wrapped around a central rod, positioned inside the first antenna's radiating elements. This nested configuration allows both antennas to coexist in a compact form factor while operating in different frequency bands, thereby expanding the overall frequency bandwidth without proportionally increasing device complexity
Solution Approach 2:
The antenna system is designed to perform multiple functions across different frequency bands. The first antenna handles GNSS frequencies while the second antenna handles Iridium and UHF frequencies. Both antennas share a common ground plane and are integrated into a single system, enabling multi-band operational versatility from a unified structure
2Adaptability or versatility
If multiple separate antennas are used to cover different frequency bands, then the frequency bandwidth is improved, but the device size and installation space requirements increase
Solution Approach 1:
The second antenna is physically nested within the first antenna's structure. The radiating elements of the second antenna are positioned inside the space occupied by the first antenna's radiating elements, allowing both antennas to share the same installation footprint. This nested arrangement significantly reduces the required installation space compared to using separate antennas
Solution Approach 2:
Both antennas share a common ground plane structure, merging their support infrastructure. The feed networks and grounding systems are integrated into a unified structure, reducing the overall space requirements and simplifying installation compared to separate antenna systems
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 system provides improved bandwidth and gain across multiple frequency bands, including GNSS, Iridium, and UHF, with enhanced impedance matching and reduced size requirements for transceiver installation, while maintaining right-hand circularly polarized radiation from zenith to near the horizon.
Implementation Method 1
Each of the radiating arms comprises a driven arm, a folded arm, and a capacitance that couples respective driven and folded arms
Data Source
AI summary
A multi-use antenna system that can be used in, for example, integrated communications and navigation capability is provided. In an embodiment, an antenna system is provided. The antenna system includes a first antenna having a plurality of radiating elements substantially wrapped around an axis and a second antenna located within the first antenna. The first and second antennas are coupled to the same ground plane and are configured to operate in different frequency bands.