Cavity Filter Connecting Structure for RF Tolerance Absorption

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Solution Overview

Problem

Current cavity filters for massive MIMO antennas face challenges in achieving a slimmer, more compact structure with embedded RF connectors, minimizing assembly tolerance, maintaining uniform frequency characteristics, and preventing signal loss due to separable RF pins, while ensuring constant contact area and easy assembly.

Innovation Solution

The proposed solution involves a cavity filter design with an RF connector embedded in the filter body's thickness direction, featuring a connecting structure that absorbs assembly tolerance through lateral tension and elastic support, maintaining constant contact area and frequency characteristics, and allowing relative motion to prevent signal loss.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

If the cavity filter is designed with a slimmer and more compact structure with embedded RF connectors, then the filter size is reduced, but the assembly tolerance accumulation increases

Engineering Contradiction:
Improvefilter sizeVSAvoidassembly tolerance
Core Design Contradiction:
Volume of moving objectVSManufacturing precision

Solution Approach 1:

The connecting structure is divided into multiple functional parts: a body portion embedded in the filter, a protruding portion extending outward, and a fastening portion with engagement features. This segmentation allows each part to be optimized independently while maintaining overall precision.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The connecting structure is pre-assembled with the filter body before final installation. The protruding portion and fastening portion are positioned and fixed in advance, which minimizes tolerance accumulation during the final assembly process by reducing the number of separate positioning operations.

Inventive Principle:
Principle #10Preliminary action

2Ease of manufacture

If separable RF pins are used for mounting, then the ease of assembly is improved, but signal loss occurs due to connection instability

Engineering Contradiction:
Improveassembly easeVSAvoidsignal transmission
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The connecting structure merges the mounting function and electrical connection function into a single integrated component. The fastening portion with engagement features simultaneously secures the mechanical connection and ensures stable electrical contact, eliminating the need for separate RF pins while maintaining signal integrity.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The contact surfaces and engagement features of the connecting structure incorporate curved or rounded geometries that distribute contact pressure evenly, ensuring consistent electrical contact area and stable signal transmission while maintaining ease of assembly.

Inventive Principle:
Principle #14Spheroidality (Curvature)

3Reliability

If the contact area between connected members is increased to prevent signal loss, then the signal transmission is improved, but the device complexity increases

Engineering Contradiction:
Improvesignal transmissionVSAvoidconnection structure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

Instead of uniformly increasing the entire contact area, the design concentrates the contact area at specific critical locations where electrical connection is most important. The fastening portion features localized engagement surfaces that provide sufficient contact area for reliable signal transmission without requiring a complex overall structure.

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP3809522B1Connecting structure and cavity filter comprising the same
Publication Date: 2023.11.08 KMW INC
  • EP3809522B1 patent drawingFigure 1
  • EP3809522B1 patent drawingFigure 2
  • EP3809522B1 patent drawingFigure 3

AI summary

The present invention relates to a cavity filter and a connecting structure included therein. The cavity filter includes: an RF signal connecting portion spaced apart, by a predetermined distance, from an outer member having an electrode pad provided on a surface thereof; and a terminal portion configured to electrically connect the electrode pad of the outer member and the RF signal connecting portion so as to absorb assembly tolerance existing at the predetermined distance and to prevent disconnection of the electric flow between the electrode pad and the RF signal connecting portion, wherein the terminal portion includes: first side terminal contacted with the electrode pad; and the second side terminal connected to the RF signal connecting portion, wherein at least any one of the first side terminal and the second side terminal has a housing space in which the other side terminal is housed, and a part of the at least one side terminal is elastically deformed by an assembly force provided by an assembler, and applies lateral tension to the other side terminal while elastically supporting the other side terminal toward the electrode pad. Therefore, the cavity filter can efficiently absorb assembly tolerance which occurs through assembly design, and prevent disconnection of an electric flow, thereby preventing degradation in performance of an antenna device.