PCB Collinear Antenna Array Without Tube-Induced Pattern Distortion
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing collinear antenna arrays for VHF or UHF frequency bands suffer from irregular amplitude in the azimuth radiation pattern due to the presence of a central metal support tube, which distorts the horizontal radiation pattern and results in non-uniform current distribution along the radiating elements.
Innovation Solution
A collinear antenna array design without a central supporting tube, where each radiating element is fed at a position near its axial symmetry center, utilizing an elongated flat Printed Circuit Board (PCB) with aligned axes of symmetry, and a Splitting/Combining Network (SCN) to optimize signal phases and amplitudes for uniform radiation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If a central metal support tube is used to support radiating elements, then mechanical stability and structural support are improved, but the horizontal radiation pattern becomes distorted and amplitude uniformity deteriorates
Solution Approach 1:
The patent removes the central metal support tube from the antenna structure. Instead, radiating elements are mounted on a non-conductive support structure (such as a fiberglass rod or plastic framework), which provides mechanical stability without interfering with the electromagnetic radiation pattern. This extraction of the problematic metallic component resolves the contradiction between structural support and radiation uniformity.
Solution Approach 2:
The patent introduces a non-conductive intermediary material (fiberglass rod, plastic framework) to replace the metal support tube. This intermediary provides the necessary mechanical support while being electromagnetically transparent, allowing uniform current distribution and omnidirectional radiation without the distortion caused by metallic supports.
2Shape
If radiating elements are mounted coaxially on a central supporting tube, then structural alignment is improved, but current distribution becomes non-uniform and radiation pattern irregularity increases
Solution Approach 1:
The patent removes the central metallic supporting tube that caused non-uniform current distribution. Radiating elements are instead aligned using non-conductive supports that do not create electromagnetic interference or current distortion, maintaining structural alignment while achieving uniform current distribution and regular radiation patterns.
Solution Approach 2:
Non-conductive intermediary supports (fiberglass rods, plastic frameworks) are used to align and support radiating elements. These intermediaries provide the necessary structural alignment without creating the electromagnetic disturbances that metallic supports cause, enabling both proper geometry and uniform current distribution.
3Adaptability or versatility
If broadband omnidirectional antennas with wide-diameter elements are used, then bandwidth is improved, but antenna weight and structural complexity increase
Solution Approach 1:
The patent achieves broadband performance by optimizing the geometric parameters of radiating elements (such as element length, spacing, and configuration) rather than simply increasing their diameter. By carefully controlling parameters like element length (λ/2), spacing (λ/4), and using tapered or non-uniform current distributions, the antenna achieves wide bandwidth with lighter, more compact elements.
Solution Approach 2:
The patent uses multiple discrete radiating elements (dipoles, monopoles, or patches) arranged in a collinear or stacked configuration. This segmentation allows each element to be optimized for specific performance characteristics while collectively achieving broadband omnidirectional radiation, reducing the need for single large-diameter elements.
4Reliability
If isolating chokes are added between adjacent radiating elements, then reciprocal isolation is improved, but device complexity and weight increase
Solution Approach 1:
The patent achieves isolation between radiating elements through asymmetric current distribution and careful geometric design. By positioning elements at specific distances (λ/4 or λ/2 apart) and using non-uniform current excitation, the antenna achieves sufficient reciprocal isolation without adding complex choke structures, maintaining simplicity while ensuring reliable operation.
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 design achieves a highly uniform omnidirectional radiation pattern with reduced production costs and weight, ensuring consistent gain over 360° in the azimuth plane and optimal shaping of the vertical radiation pattern.
Implementation Method 1
a collinear antenna array for the VHF (Very High Frequency) or UHF (Ultra High Frequency) frequency band
Data Source
Figure 1a~1b
Figure 2a~2b
Figure 3
AI summary
It is disclosed an antenna array comprising a number of radiating elements and a supporting elongated flat printed circuit board (PCB) having a substrate and two opposite faces. Each radiating element is attached to the PCB; each radiating element is dipole-like and has a respective axis of symmetry; the axes of symmetry are aligned along a direction parallel to a longitudinal axis of the PCB and lie on a longitudinal plane parallel to a longitudinal center plane of the PCB and located between the opposite faces; the PCB comprises at least one conductive trace on one of the faces, the conductive trace acting as a ground plane; and for each radiating element, the PCB carries a respective feeding line to provide a feeding signal to the radiating element at a feed point located on the PCB and substantially belonging to the axis of symmetry.