Capacitively Shielded Housing for Antenna Devices

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Current mobile radio antenna designs require a large number of screws for assembly, leading to undefined contact points and tolerance deviations, which result in undesirable intermodulation and poor shielding against high-frequency interference due to gaps and irregularities between housing walls and cover parts.

Innovation Solution

A capacitively shielded housing design that uses insulating layers to create a capacitive coupling between the reflector housing and the shielding plate, eliminating the need for screws and ensuring parallel contact surfaces to prevent intermodulation and improve shielding efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If a large number of screws are used to assemble the housing and shielding plate, then the shielding effectiveness is improved, but the manufacturing complexity and assembly time increase

Engineering Contradiction:
Improveshielding effectivenessVSAvoidassembly complexity
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The patent extracts the fastening function from the shielding assembly by removing the need for screws entirely. The shielding plate is retained solely by capacitive coupling through contact areas, eliminating mechanical fasteners while maintaining shielding effectiveness.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent replaces the mechanical screw-fastening system with an electrical field-based capacitive coupling system. The contact areas between the housing and shielding plate create capacitive coupling that provides both retention and shielding without mechanical connection.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Reliability

If screws are used to fix the shielding plate, then the shielding is secured, but undefined contact points and tolerance deviations occur causing intermodulation

Engineering Contradiction:
Improveshielding reliabilityVSAvoidcontact point precision
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The patent removes the screw fastening mechanism entirely, eliminating the source of contact point variability and tolerance accumulation. The shielding plate is held in position through capacitive coupling alone, ensuring consistent contact without mechanical intervention.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent changes the retention mechanism from mechanical (screws creating point contacts) to electrical field-based (capacitive coupling across contact areas). This parameter change eliminates undefined contact points and tolerance deviations that cause intermodulation.

Inventive Principle:
Principle #35Parameter changes

3Ease of manufacture

If press-fit nuts are used for assembly, then preliminary fixing points are created, but misalignments occur leading to poor contact conditions

Engineering Contradiction:
Improveassembly easeVSAvoidalignment precision
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The patent eliminates press-fit nuts and all intermediate fastening components. The shielding plate is retained directly through capacitive coupling between contact areas, removing multiple alignment-critical interfaces and their associated misalignment risks.

Inventive Principle:
Principle #2Taking out (Extraction)

4Reliability

If galvanic contact is used between housing and shielding plate, then electrical connection is achieved, but surface damage and altered contact conditions occur

Engineering Contradiction:
Improveelectrical connection reliabilityVSAvoidsurface damage
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent introduces an insulating layer as an intermediary between the housing and shielding plate contact areas. This dielectric layer prevents direct galvanic contact and associated surface damage while maintaining capacitive coupling for both retention and shielding functionality.

Inventive Principle:
Principle #24Intermediary (Mediator)

5Object-affected harmful factors

If multiple screws are used to assemble components, then the shielding is secured, but assembly time and costs increase

Engineering Contradiction:
Improveshielding effectivenessVSAvoidassembly productivity
Core Design Contradiction:
Object-affected harmful factorsVSProductivity

Solution Approach 1:

The patent removes all screw fasteners from the assembly process. The shielding plate is installed and retained in a single operation through capacitive coupling alone, dramatically reducing assembly time and complexity while maintaining shielding effectiveness.

Inventive Principle:
Principle #2Taking out (Extraction)

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 design reduces the risk of intermodulation, enhances high-frequency shielding, and simplifies assembly by eliminating the need for screws, while allowing for precise alignment and force-fitted contact, thus improving the overall structure's performance and reducing assembly time and costs.

Implementation Method 1

corresponding contact areas or flanges of the housing and of the shielding plate are not galvanically contacted with one another in their contact area, but are capacitively coupled to one another by means of an insulating layer or insulating film

Methodology Applied
Scientific EffectCapacitive coupling: Capacitance

Data Source

PatentEP3175510B1Capacitively shielded housing, in particular capacitively shielded component housing for an antenna device
Publication Date: 2019.12.18 TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)
  • EP3175510B1 patent drawingFigure 1
  • EP3175510B1 patent drawingFigure 2a
  • EP3175510B1 patent drawingFigure 2b

AI summary

The invention relates to an improved capacitively shielded housing, in particular a capacitively shielded component housing for a mobile radio antenna, which is characterized, inter alia, by the following features: - comprising an electrically conductive component and/or reflector housing (16), the component and/or reflector housing (16) has an opening region (30), which is shielded with respect to HF radiation by a shielding cover or a shielding plate (31), the contact or anchoring cover segments (45) of the shielding cover or of the shielding plate (31) are arranged against the component and/or reflector housing (16) immediately adjacent to and in parallel with the contact or anchoring housing segments (122), an insulating layer (47) being interposed, and the planar contact or anchoring housing segments (122) and the planar contact or anchoring cover segments (45) are oriented parallel to or at angle to an insertion or mounting direction (E) and/or a central axis (Z) extending through the component and/or reflector housing (16), namely at an angle α according to the following condition: 0° < α < 90°.