MIMO Antenna Isolation via Metal Cavity Segmentation

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Solution Overview

Problem

Full-metal outer shells in wireless communication devices cause signal shielding and interference, and MIMO technology faces challenges in ensuring simultaneous operation of multiple antennas without interference.

Innovation Solution

A MIMO antenna device with a metal shell and isolate wall partitioning the cavity into independent regions for each antenna, using feed units and adjustable capacitors to minimize interference and optimize signal transmission and reception.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If a full-metal outer shell is used, then aesthetic appearance and structural strength are improved, but signal shielding and interference occur

Engineering Contradiction:

Improvestructural strengthVSAvoidsignal shielding

Core Design Contradiction:

StrengthVSObject-affected harmful factors

Solution Approach 1:

The metal cavity is segmented into first and second cavities by the metal isolate wall, creating independent regions for different antenna groups. This segmentation allows each antenna group to operate independently without mutual interference, resolving the signal shielding problem while maintaining the full-metal outer shell structure.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different regions of the metal cavity are assigned different functions: the first cavity houses the battery region with the first antenna group, while the second cavity contains the second antenna group. This local differentiation optimizes signal transmission in each region while maintaining overall structural integrity.

Inventive Principle:

Principle #3Local quality

2Productivity

If multiple antennas operate simultaneously for MIMO technology, then signal transmission and reception capability is improved, but signal interference between antennas occurs

Engineering Contradiction:

Improvesignal transmission capabilityVSAvoidsignal interference

Core Design Contradiction:

ProductivityVSObject-affected harmful factors

Solution Approach 1:

The antenna system is segmented into two independent groups operating in separate cavities. The metal isolate wall physically separates the first antenna group in the first cavity from the second antenna group in the second cavity, enabling simultaneous MIMO operation without signal interference between antenna groups.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The metal isolate wall acts as an intermediary structure between the two antenna groups. It provides electromagnetic isolation while allowing each group to function independently, thus enabling MIMO technology to operate effectively without mutual interference.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Object-affected harmful factors

If a nonmetal spacer is added to reduce antenna shielding, then signal radiation is improved, but aesthetic appearance and structural strength deteriorate

Engineering Contradiction:

Improveantenna shieldingVSAvoidstructural strength

Core Design Contradiction:

Object-affected harmful factorsVSStrength

Solution Approach 1:

The metal shell, which originally caused signal shielding, is converted into a beneficial structure by creating internal metal cavities with isolate walls. These metal structures now serve as electromagnetic shields for individual antenna groups while maintaining the external full-metal aesthetic, turning the harmful shielding effect into a useful isolation mechanism.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

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 effective signal transmission and reception with high isolation between antennas, achieving MIMO functionality while maintaining a full-metal outer shell without compromising aesthetics or structural strength.

Implementation Method 1

a metal isolate wall, the metal isolate wall is provided between the metal shell and the metal piece, the metal isolate wall partitions the metal cavity into a first cavity and a second cavity

Methodology Applied

Scientific EffectElectromagnetic isolation: Faraday Cage

Implementation Method 2

a first feed unit, the first feed unit feeds toward the first cavity to form a first antenna; and a second feed unit, the second feed unit feeds toward the second cavity to form a second antenna

Methodology Applied

Scientific EffectElectromagnetic radiation: Electromagnetic Induction

Data Source

PatentUS10601129B2MIMO antenna device and mobile communication device

Publication Date: 2020.03.24 MOLEX INTERCONNECT SHANGHAI

AI summary

The present disclosure provides a MIMO antenna device and a mobile communication device which comprises a metal shell and a metal piece, the metal shell comprises a metal back plate and a metal frame which are integrally formed, the metal frame surrounds the metal back plate, the metal piece and the metal shell enclose to form a metal cavity, the metal cavity comprises a battery region used to place a battery assembly and a non-battery region outside the battery region; a metal isolate wall is provided between the metal shell and the metal piece, the metal isolate wall partitions the metal cavity into a first cavity and a second cavity, the first cavity contains the battery region; a first feed unit feeds toward the first cavity to form a first antenna; and a second feed unit feeds toward the second cavity to form a second antenna. The MIMO antenna device and the mobile communication device in the present disclosure form a MIMO antenna device with high isolation through the first antenna and the second antenna, so as to achieve communication in the case of a full-metal outer shell.