Antenna With Partially Saturated Ferromagnetic Substrate
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Electrically small antennas face challenges with impedance matching, particularly in high-power applications, leading to unstable impedance and narrow bandwidth, which reduces radiation efficiency and makes them unsuitable for broadband operations.
Innovation Solution
The use of a dispersive ferromagnetic substrate with partial saturation, allowing for stabilization of impedance and increased bandwidth while maintaining radiation efficiency, achieved through local and gradual modification of magnetic characteristics using magnets or materials with low relative magnetic permeability and loss tangent.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a dispersive ferromagnetic substrate is used to stabilize impedance and increase bandwidth, then the bandwidth and impedance stability are improved, but the radiation efficiency is significantly reduced
Solution Approach 1:
The patent applies local quality by creating a non-uniform magnetic field distribution within the ferromagnetic substrate through strategic placement of magnets. This results in spatially varying magnetic permeability, where different regions of the substrate have different magnetic properties. The partially saturated regions have reduced magnetic losses while maintaining impedance stabilization, thus resolving the contradiction between bandwidth improvement and radiation efficiency maintenance
Solution Approach 2:
The patent changes the magnetic parameter (magnetic permeability) of the ferromagnetic substrate by applying external magnetic fields from magnets. This transforms the substrate from a uniformly high-loss dispersive ferromagnetic material to a partially saturated material with spatially varying permeability. The parameter change reduces magnetic losses in certain regions while preserving the impedance stabilizing effect, thereby improving radiation efficiency without sacrificing bandwidth
2Volume of moving object
If the antenna size is reduced to be ultra-compact vertically, then the compactness is improved, but the radiation efficiency deteriorates due to strong reactive impedance component
Solution Approach 1:
The patent changes the magnetic parameters of the substrate material through partial saturation to improve the antenna's input impedance characteristics. This allows the ultra-compact antenna to achieve better impedance matching and reduced reactive components, thereby improving radiation efficiency despite the reduced size
Solution Approach 2:
The patent uses a composite structure combining ferromagnetic substrate with magnet materials to create a hybrid system. This composite approach enables the antenna to maintain compact dimensions while achieving improved radiation efficiency through the synergistic interaction between the ferromagnetic material and the applied magnetic fields
3Volume of moving object
If high magnetic permeability ferromagnetic material is used to miniaturize the antenna, then the antenna size is reduced, but the magnetic losses increase causing reduced radiation efficiency
Solution Approach 1:
The patent creates non-uniform magnetic permeability distribution within the ferromagnetic substrate by applying external magnetic fields from magnets. This results in spatially varying properties where some regions maintain high permeability for miniaturization while other regions are partially saturated to reduce magnetic losses, thus resolving the contradiction between size reduction and loss reduction
Solution Approach 2:
The patent changes the magnetic permeability parameter of the ferromagnetic substrate from a uniformly high value to a spatially varying value through partial saturation. This parameter transformation reduces magnetic losses in specific regions while preserving the miniaturization effect in other regions, thereby achieving both size reduction and loss reduction simultaneously
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 solution results in an ultra-compact, broadband antenna with improved radiation efficiency and directivity, capable of operating across various frequency bands with reduced heating during high-power emissions.
Implementation Method 1
The antenna comprises a dispersive ferromagnetic substrate, called dispersive ferrite, whose magnetic characteristics are changed locally and gradually
Implementation Method 2
The means for local modification of the magnetic characteristics of the dispersive ferrite are a magnet (permanent magnet or electromagnet), or at least one piece of material having a low relative magnetic permeability and a low loss tangent
Data Source
Figure 1~2
Figure 3~6
Figure 7~9
AI summary
The invention relates to an antenna comprising at least two non-ferrous metal plates, at least one first plate forming a radiating portion (4H) and a second plate forming a ground plane (4B), at least one substrate arranged between the ground plane (4B) and the radiating portion (4H), and an exciter having a length at least equal to the thickness of the substrate, said exciter extending between the ground plane (4B) and the radiating portion (4H) and being connected to the radiating portion (4H), and adapted to supply the antenna, characterised in that the substrate is a dispersive ferromagnetic substrate referred to as a dispersive ferrite (1), the magnetic properties thereof being a high relative magnetic permeability of between 10 and 10,000 and a high magnetic loss tangent greater than 0.1, the antenna comprising means for gradually locally reducing the magnetic properties of the dispersive ferrite (1).