Curved-Wall Waveguide Low-Pass Filter for Compact Signal Rejection

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Solution Overview

Problem

Conventional waveguides with filters for electromagnetic signals are challenging to manufacture and require significant space or cost due to their complex structures, such as long stepped impedance filters or expensive thin iris filters, which often have narrow rejection bands.

Innovation Solution

A waveguide with a curved-wall low-pass filter design that includes a cavity feature with a greater depth than the input and output ports, utilizing curved or elliptical bottom walls to allow low-frequency electromagnetic energy while rejecting high-frequency energy, potentially reducing manufacturing complexity and space requirements.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional filters (stepped impedance filters or thin iris filters) are used, then signal rejection is achieved, but manufacturing complexity and cost increase

Engineering Contradiction:
Improvesignal rejectionVSAvoidmanufacturing complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies curvature to the bottom wall of the waveguide cavity, transforming it from a flat surface to a curved surface. This curved bottom wall creates a resonant cavity that provides the necessary signal rejection properties. The curvature allows the cavity to resonate at specific frequencies, effectively rejecting unwanted signals while maintaining a simpler, more manufacturable structure compared to conventional stepped impedance or thin iris filters.

Inventive Principle:
Principle #14Spheroidality (Curvature)

2Reliability

If conventional filters are used, then signal rejection is achieved, but the structure requires significant space

Engineering Contradiction:
Improvesignal rejectionVSAvoidfilter space
Core Design Contradiction:
ReliabilityVSVolume of moving object

Solution Approach 1:

The patent utilizes the depth dimension of the waveguide cavity by curving the bottom wall to create a resonant structure. This dimensional approach allows the filter to achieve effective signal rejection within a compact volume. The curved bottom wall creates a three-dimensional resonant cavity that efficiently rejects signals without requiring the extended length or complex multi-section structures of conventional filters.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Reliability

If conventional filters are used, then signal rejection is achieved, but the structure is expensive to manufacture

Engineering Contradiction:
Improvesignal rejectionVSAvoidmanufacturing cost
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The curved bottom wall design simplifies manufacturing by eliminating the need for complex stepped impedance structures or precision thin iris assemblies. The curvature can be achieved through standard forming processes, reducing the number of discrete parts and assembly steps. This approach maintains effective signal rejection while significantly lowering manufacturing complexity and cost compared to conventional filter designs.

Inventive Principle:
Principle #14Spheroidality (Curvature)

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 curved-wall low-pass filter achieves effective signal rejection (at least 10 dB within 2 GHz for a 5 GHz bandwidth) while being easier to manufacture and more compact, potentially reducing costs and footprint in applications like radar systems.

Implementation Method 1

a low-pass filter portion configured to allow low-frequency electromagnetic energy therethrough and reject high-frequency electromagnetic energy

Methodology Applied
Scientific EffectLow-pass filtering: Filter (electronic)

Data Source

PatentEP4465439A1Waveguide with a curved-wall low-pass filter
Publication Date: 2024.11.20 APTIV TECHNOLOGIES AG
  • EP4465439A1 patent drawingFigure 1
  • EP4465439A1 patent drawingFigure 2
  • EP4465439A1 patent drawingFigure 3

AI summary

A waveguide with a curved-wall low-pass filter is described herein. The waveguide comprises a low-pass filter portion configured to allow low-frequency electromagnetic energy therethrough and reject high-frequency electromagnetic energy. The low-pass filter portion comprises an input port, an output port, and a cavity feature that is formed between the input port and the output port. The cavity feature has a greater depth than respective depths of the input port and the output port. The cavity feature comprises a bottom wall that achieves the greater depth for the cavity feature. The bottom wall comprises at least one curved portion configured to allow the cavity feature to achieve the allowance of the low-frequency electromagnetic energy and the rejection of the high-frequency electromagnetic energy. The cavity feature may allow the waveguide to have as good or better performance than traditional means while being easier to manufacture and/or taking up less space.