Antenna Coupling Element for Wideband Resonance
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Solution Overview
Problem
Existing antenna devices face challenges in achieving wideband characteristics due to anti-resonance issues, where the resonant frequency of passive radiating elements coincides with anti-resonant frequencies, preventing effective magnetic field coupling and resulting in a lack of wideband effects.
Innovation Solution
The implementation of an antenna coupling element with a first coil and a second coil, where the winding directions are opposite, and a capacitance is generated between the coils, allowing current to flow through the second radiating element via capacitance even at anti-resonant frequencies, ensuring resonance and contributing to a wider bandwidth.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the resonant frequency of the passive radiating element is set close to the harmonic resonant frequency of the feed radiating element to achieve wideband characteristics, then the bandwidth is improved, but when the resonant frequency coincides with the anti-resonant frequency, magnetic field coupling fails and the wideband effect is lost
Solution Approach 1:
A coupling element is introduced as an intermediary between the feed radiating element and the passive radiating element. This coupling element includes a first coil coupled to the feed radiating element and a second coil coupled to the passive radiating element, with a capacitor connecting the coils. The intermediary structure enables current to reach the passive radiating element through both magnetic field coupling and capacitive coupling paths, ensuring reliable operation even when resonant and anti-resonant frequencies coincide.
Solution Approach 2:
The invention changes the coupling mechanism by introducing a capacitor with specific capacitance value in the coupling element. This parameter modification allows the system to operate effectively at frequencies where traditional magnetic field coupling would fail, particularly when the passive radiating element's resonant frequency coincides with the feed radiating element's anti-resonant frequency.
2Device complexity
If magnetic field coupling is used to couple the passive radiating element to the feed radiating element, then the antenna structure is simplified, but current cannot flow through the feed radiating element at anti-resonant frequency, preventing coupling
Solution Approach 1:
The coupling element acts as an intermediary that provides an alternative current path through capacitive coupling. The first coil is coupled to the feed radiating element and the second coil is coupled to the passive radiating element, with a capacitor connecting the two coils. This intermediary structure enables current to flow through the passive radiating element even when the feed radiating element is at anti-resonant frequency, thereby maintaining frequency band coverage without significantly increasing structural complexity.
3Adaptability or versatility
If the passive radiating element is added to extend bandwidth coverage, then the frequency band coverage is improved, but additional conductive members are required, increasing device size
Solution Approach 1:
The coupling element merges multiple functions into a single component: it provides magnetic field coupling between the feed radiating element and passive radiating element, incorporates capacitive coupling through an integrated capacitor, and enables operation at anti-resonant frequencies. This merging approach achieves wideband frequency coverage without requiring separate additional conductive members, thereby minimizing device size while maintaining adaptability across frequency bands.
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 enables the passive radiating element to resonate effectively even when its resonant frequency coincides with the anti-resonant frequency of the feed radiating element, resulting in a wideband antenna device that covers a wide frequency band without the need for additional conductive members, facilitating miniaturization and integration in electronic devices.
Implementation Method 1
the passive radiating element is coupled to the feed radiating element with a magnetic field
Implementation Method 2
a capacitance is generated between the coils, allowing current to flow through the second radiating element via capacitance
Implementation Method 3
the resonant frequency of passive radiating elements coincides with anti-resonant frequencies, preventing effective magnetic field coupling
Data Source
AI summary
An antenna device includes first and second radiating elements, and an antenna coupling element. The antenna coupling element includes a primary coil electrically connected between the first radiating element and a feed circuit and a secondary coil inductively coupled to the primary coil and electrically connected between the second radiating element and a ground. A capacitor is provided between the primary coil and the secondary coil, thus causing current to flow from the primary coil to the secondary coil or the second radiating element via the capacitor even at an anti-resonant frequency of the first radiating element.