PCB Collinear Antenna Array Feeding for Stable Omnidirectional Radiation

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Solution Overview

Problem

Existing series-fed omnidirectional collinear antenna arrays are complex in structure, have narrow bandwidth, are long and unstable, and fail to adapt to different application scenarios due to increased input impedance and mechanical stability issues.

Innovation Solution

A series-fed omnidirectional collinear antenna array with phase delayers connected in series, where the circuit wire on a dielectric plate has varying lengths, widths, and spacings set according to preset rules to control phase and amplitude fed to each antenna radiating unit, improving radiation efficiency and gain.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If coaxial line segment translocation interconnection is used to implement omnidirectional collinear antenna array, then the array can direct energy into non-radiating section and radiate in positive half cycle, but the input impedance increases with increase of units resulting in narrow bandwidth

Engineering Contradiction:
Improveradiation pattern stabilityVSAvoidbandwidth
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent transforms the traditional coaxial line feeding structure into a planar printed circuit board transmission line structure. By changing the feeding mechanism from coaxial line segment translocation to PCB trace interconnection, the input impedance is controlled and stabilized across different array configurations, thereby expanding the operational bandwidth while maintaining reliable omnidirectional radiation patterns.

Inventive Principle:
Principle #35Parameter changes

2Productivity

If circular gap-fed coaxial dipole array with large unit diameter is used, then wider operating bandwidth can be provided, but the structure becomes complicated

Engineering Contradiction:
ImprovebandwidthVSAvoidstructure complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent replaces the mechanical coaxial dipole structure with a planar printed circuit board implementation. Instead of using physical coaxial lines, dipole separators, and choke lines in three-dimensional space, the invention uses PCB transmission lines and ground planes to achieve the same electromagnetic functionality in a two-dimensional plane, significantly simplifying the overall structure while maintaining wide bandwidth performance.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The invention transitions from a three-dimensional coaxial structure to a two-dimensional planar structure on PCB. By laying out the antenna elements and feeding networks on a flat substrate, the complex spatial interconnections of traditional coaxial arrays are replaced with planar trace routes, reducing structural complexity while preserving the wide bandwidth characteristics.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Reliability

If traditional collinear antenna array structure is used, then omnidirectional radiation can be achieved, but the array becomes long in length and unstable in mechanical stability

Engineering Contradiction:
Improveomnidirectional radiationVSAvoidarray length
Core Design Contradiction:
ReliabilityVSLength of stationary object

Solution Approach 1:

The patent consolidates the traditional vertically stacked collinear antenna structure into a planar configuration on PCB. Instead of extending the antenna array vertically over a long distance, the invention lays out multiple antenna elements in a two-dimensional plane on the circuit board, achieving the same omnidirectional radiation pattern while dramatically reducing the overall length and improving mechanical stability.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

4Reliability

If traditional collinear antenna array structure is used, then omnidirectional radiation can be achieved, but the array becomes prone to mechanical stability and manufacturability problem

Engineering Contradiction:
Improveradiation pattern stabilityVSAvoidmanufacturability
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent replaces traditional mechanical assembly processes with PCB manufacturing processes. Instead of manually assembling coaxial connectors, dipole elements, and choke lines, the invention uses standard PCB fabrication techniques including printed transmission lines, plated through-holes, and surface mount components, significantly improving manufacturability and consistency while maintaining stable radiation patterns.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

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 configuration enhances radiation efficiency, reduces sidelobe amplitude, and achieves stable radiation patterns, allowing the antenna array to adapt to various application scenarios with improved manufacturability and mechanical stability.

Implementation Method 1

the circuit wire on the phase delayer has varying lengths, widths, and spacings set according to preset rules to control phase and amplitude fed to each antenna radiating unit

Methodology Applied
Scientific EffectElectromagnetic wave propagation: Electromagnetic Induction

Implementation Method 2

the circuit wire on a dielectric plate has varying lengths, widths, and spacings set according to preset rules

Methodology Applied
Scientific EffectDielectric insulation: Dielectric

Implementation Method 3

two ends of the circuit wire are connected to the antenna radiating unit, improving radiation efficiency and gain

Methodology Applied
Scientific EffectElectromagnetic radiation: Electromagnetic Induction

Data Source

PatentEP3534461B1Method and apparatus for omnidirectional series-fed collinear antenna arrays with stable performance
Publication Date: 2023.10.04 NORSAT INTERNATIONAL
  • EP3534461B1 patent drawingFigure 1
  • EP3534461B1 patent drawingFigure 2a
  • EP3534461B1 patent drawingFigure 2b

AI summary

The embodiments of the present invention disclose a collinear antenna assembly and a series-fed omnidirectional collinear antenna array, wherein the collinear antenna assembly includes a plurality of phase delayers connected in series, and an end portion of each phase delayer is connected to an antenna radiating unit; the phase delayer includes a circuit wire printed on a dielectric plate, two ends of the circuit wire are connected to the antenna radiating unit, a wire length, a wire width and a wire spacing of the circuit wire are set based on preset wiring rules, the wire lengths, the wire widths and the wire spacing of the circuit wires of the phase delayers set based on different preset wiring rules are different, so that a phase and an amplitude fed to each antenna radiating unit are accurately controlled, thus effectively controlling a maximum radiation efficiency of each antenna radiating unit, improving a gain and a total radiation efficiency of the antenna array, reducing a sidelobe amplitude of the antenna array, and obtaining a stable radiation downtilt, so as to adapt to different application scenarios.