Bihelical Antenna Phase Combining for Multipath Interference
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Solution Overview
Problem
Rural airports face challenges in data transmission due to multipath interference, which is not effectively addressed by traditional antennas, especially in areas with uneven topography, extreme weather, and safety-induced height restrictions, leading to inadequate network connectivity and potential aviation safety risks.
Innovation Solution
The use of a bihelical antenna system with a phase adjuster and signal combiner that employs circular polarization to mitigate multipath interference by combining signals from an outer and inner helix, allowing for effective data transmission over long ranges at low elevations, thereby reducing signal loss and enhancing power efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional antennas are used for data transmission in rural areas, then the system is simple and cost-effective, but multipath interference from ground reflections causes signal loss and reduces transmission reliability
Solution Approach 1:
The antenna system is divided into two separate helical antennas: a direct-path antenna for receiving signals traveling directly from the transmitter, and a reflected-path antenna for receiving signals that have reflected off the ground. This segmentation allows each antenna to be optimized for its specific signal path, improving overall reception reliability by capturing both direct and reflected signals separately before combining them
Solution Approach 2:
The inner helical antenna is physically nested within or positioned inside the outer helical antenna structure. This nested configuration allows both antennas to coexist in a compact arrangement while maintaining their distinct functions for receiving direct and reflected signals, reducing the overall system footprint without compromising performance
2Reliability
If antennas are mounted at high elevations to avoid multipath interference, then signal quality improves, but installation becomes difficult and costly due to terrain and safety restrictions
Solution Approach 1:
The system automatically adapts to multipath conditions by using two antennas that independently receive direct and reflected signals. The phase adjuster and signal combiner automatically process these signals to compensate for ground reflections, eliminating the need for manual high-elevation installation while achieving the same reliability benefit through electronic rather than mechanical means
Solution Approach 2:
The system changes the operational parameters of the antenna elements by introducing adjustable phase delays to the reflected-path antenna signal. This phase adjustment allows the system to electronically compensate for the effects of ground reflections and optimize signal combination, achieving reliable transmission without requiring physical elevation changes
3Loss of energy
If single-antenna systems are used, then the device complexity is low, but signal power is lost due to destructive interference from multipath reflections
Solution Approach 1:
The system merges the signals from two separate antennas by using a signal combiner that combines the direct-path antenna output and the reflected-path antenna output. This merging process allows constructive interference between the two signals, recovering power that would otherwise be lost to destructive interference in a single-antenna system, while the phase adjuster optimizes the combination to maximize signal strength
Solution Approach 2:
The system converts the harmful effect of ground-reflected signals, which normally cause destructive interference and power loss, into a beneficial resource. By using a dedicated reflected-path antenna to capture these reflected signals and combining them with direct-path signals through phase-adjusted merging, the system transforms what was previously a source of interference into a source of additional signal power
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 provides a cost-effective and efficient data transmission system that overcomes multipath interference, enabling reliable network connectivity and improved aviation safety by recovering lost signal power and increasing the range of data transmission, even in challenging geographical conditions.
Implementation Method 1
The use of a bihelical antenna system with a phase adjuster and signal combiner that employs circular polarization to mitigate multipath interference
Implementation Method 2
mitigating multipath radio frequency interference
Implementation Method 3
apply an adjustable phase delay to the input signal
Implementation Method 4
A phase adjuster, or phase trimmer, can be configured to receive the first electromagnetic signal as an input signal, apply an adjustable phase delay to the input signal
Implementation Method 5
a signal combiner can be configured to receive the adjusted electromagnetic signal and the second electromagnetic signal and output a combined electromagnetic signal
Data Source
AI summary
A radio frequency transmission system and methods for mitigating multipath radio frequency interference are disclosed. Embodiments include a first helical antenna having a first radius and operable to receive a first electromagnetic signal, and a second helical antenna having a second radius and operable to receive a second electromagnetic signal. Further embodiments include a phase adjuster configured to receive the first electromagnetic signal as an input signal, apply an adjustable phase delay to the input signal, and output an adjusted electromagnetic signal. Still further embodiments include a signal combiner configured to receive the adjusted electromagnetic signal and the second electromagnetic signal and output a combined electromagnetic signal.