Multi-Antenna Isolation via Feed Element Cancellation Currents
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Solution Overview
Problem
Existing multi-antenna designs for radio apparatuses face challenges in achieving high isolation without increasing complexity and positional robustness, particularly in compact devices where implementability and positional stability are compromised due to the need for additional components and precise positional relationships.
Innovation Solution
A multi-antenna design featuring a ground plane with two distinct feeding points and feed elements that establish electromagnetic field coupling with radiating elements, allowing for high isolation and positional robustness without additional parasitic elements, using a configuration where the feed elements are separated and connected through a ground plane, enabling efficient power feeding and impedance matching.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If additional parasitic elements are added to enhance isolation, then isolation between antenna elements is improved, but device complexity and number of components increase
Solution Approach 1:
The invention extracts the isolation enhancement function from separate parasitic elements and integrates it into the feed elements themselves. By designing the feed elements with specific geometries (bent shapes, different orientations) that generate cancellation currents, the patent eliminates the need for additional parasitic elements while maintaining isolation performance.
Solution Approach 2:
The feed elements are designed to serve dual functions: power feeding and isolation enhancement. By configuring the feed elements to generate cancellation currents through their geometry and positioning, they simultaneously perform the feeding function and the isolation function that would traditionally require separate parasitic elements.
2Volume of moving object
If capacitive coupling is used to reduce space, then space utilization is improved, but positional robustness deteriorates due to sensitivity to manufacturing errors and oscillation
Solution Approach 1:
The invention replaces the mechanical contact-based capacitive coupling with electromagnetic field coupling. The feed elements are positioned near the radiating element without physical contact, using electromagnetic fields to transfer energy. This substitution eliminates the sensitivity to positional variations and manufacturing errors inherent in capacitive coupling while maintaining compact dimensions.
Solution Approach 2:
The ground plane serves as an intermediary that enables electromagnetic field coupling between the feed elements and the radiating element. By utilizing the ground plane as a reference and coupling medium, the system achieves reliable energy transfer without direct contact, improving positional robustness while maintaining compact design.
3Volume of moving object
If feed elements are positioned close to radiating elements for compact design, then space is reduced, but isolation between antenna ports deteriorates
Solution Approach 1:
The invention converts the harmful coupling effect into a beneficial isolation mechanism. By positioning feed elements close to radiating elements and configuring them to generate cancellation currents, the strong electromagnetic interaction that would normally degrade isolation is instead used to create cancellation effects that enhance isolation between antenna ports.
Solution Approach 2:
The feed elements are designed with asymmetric geometries and different orientations relative to the radiating element. This asymmetry creates directional cancellation current patterns that selectively cancel coupling in specific directions, enabling compact positioning while maintaining isolation performance.
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 design achieves high isolation and robustness against positional shifts, simplifying implementation and maintaining efficiency across varying environmental conditions, while reducing the number of components and complexity, thus enhancing the antenna's performance in compact devices.
Implementation Method 1
a radiating element that functions as a radiation conductor when power is supplied by establishing electromagnetic field coupling with the first feed element and the second feed element
Data Source
AI summary
A multi-antenna includes a ground plane; a first feeding point; a second feeding point that is different from the first feeding point; a first feed element that is connected to the first feeding point; a second feed element that is connected to the second feeding point, a cancellation electric current being generated in the second feed element; and a radiating element that functions as a radiation conductor when power is supplied by establishing electromagnetic field coupling with the first feed element and the second feed element.