Omnidirectional Antenna With Diode-Based Sectoring
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Solution Overview
Problem
Omnidirectional antennas lack the ability to selectively influence directivity in specific azimuthal directions, limiting their sectoring capabilities and integration flexibility.
Innovation Solution
A wide-band omnidirectional antenna design featuring a contact-free transition in three dimensions between a coaxial excitation line and conductive elements with rotational symmetry, incorporating radiation modifier elements like diodes or MEMS components in the tapering zone, allowing for sectoring of the angular space.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If traditional omnidirectional antenna structures are used, then good directivity in all azimuthal directions is achieved, but the ability to selectively influence directivity in specific directions is lost
Solution Approach 1:
The patent implements dynamic control of radiation patterns by using varactor diodes that can change their electrical characteristics based on applied voltage. This allows the antenna to dynamically adjust its directivity and sector coverage without physical reconfiguration, resolving the contradiction between adaptability and complexity by using electrical control instead of mechanical or structural changes.
Solution Approach 2:
The invention changes electrical parameters (capacitance values of varactor diodes) to control the radiation pattern. By varying the reverse bias voltage applied to the varactor diodes, the effective electrical length and impedance of the antenna elements are modified, enabling selective directivity control while maintaining a relatively simple fixed physical structure.
2Ease of manufacture
If contact-free transition is implemented between coaxial cable and antenna elements, then integration flexibility is improved, but manufacturing complexity increases
Solution Approach 1:
The patent introduces an intermediate tapered structure that serves as a transition zone between the coaxial cable and the antenna elements. This tapered section acts as an impedance transformer and mechanical adapter, enabling contact-free integration while simplifying the manufacturing process by providing a gradual transition that is easier to fabricate than abrupt connections.
3Adaptability or versatility
If radiation modifier elements are added to achieve sectoring, then directivity control is improved, but antenna weight and complexity increase
Solution Approach 1:
The invention extracts the radiation modification function from separate physical elements and integrates it directly into the antenna elements themselves through varactor diodes. This eliminates the need for additional heavy modifier elements while achieving the same sectoring capability, thus improving adaptability without significantly increasing weight.
Solution Approach 2:
Instead of adding physical mass to modify radiation patterns, the invention changes the electrical parameters of existing antenna elements using varactor diodes. This approach achieves sectoring capability through electrical control rather than mechanical additions, keeping the antenna lightweight while maintaining full adaptability for different radiation patterns.
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
Enables flexible control over the radiation pattern, achieving sectoring of the angular space and optimizing spatial efficiency, weight, and ease of integration, with improved directivity and reduced losses.
Implementation Method 1
modifying the radiation pattern of the antenna by means of varactor diodes
Implementation Method 2
the power being from the centre of the cones. The form of the cones enables determination of a progressive tapering zone from where the wave propagates
Data Source
AI summary
The invention relates to a wide-band omnidirectional antenna including at least a first conducting member and a second conducting member having a revolution symmetry about a common revolution axis and central openings, said members being arranged opposite each other, at least one member having a progressively flaring area, characterised in that it comprises a gap between the conducting members and a central coaxial excitation line so as to achieve a three-dimensional contactless transition between the coaxial excitation line and the conducting members and members for modifying the radiation pattern in the flaring area of the diode type for selectively radiating the gap depending on the on- or off-state of said diodes.