EMC Filter Series Resonant Circuit Harmonic Attenuation

Solution Overview

Problem

Standard EMC filter components inadequately filter harmonics in the longwave band during wireless power transmission in the automotive sector, requiring large dimensions and numerous electrical components.

Innovation Solution

A compact filter component with a series resonant circuit comprising inductance and capacitors, specifically designed to attenuate the second harmonic at 170 kHz, reducing the number of components and achieving effective noise reduction with a low quality factor and minimal capacitors.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If standard EMC filter components are used, then filtering in the longwave band is insufficient, but increasing the number of electrical components and dimensions is required to achieve adequate attenuation

Engineering Contradiction:

Improveharmonic attenuation in longwave bandVSAvoidnumber of electrical components

Core Design Contradiction:

Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The patent changes the resonant frequency parameter of the LC circuit to match the second harmonic frequency (170 kHz). By tuning the resonant circuit to resonate at the specific harmonic frequency, the filter achieves targeted attenuation of the second harmonic without requiring multiple filter stages, thus reducing component count while improving longwave band filtering performance.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent utilizes electrical resonance (analogous to mechanical vibration) by designing an LC circuit with resonant frequency matching the second harmonic. The resonant circuit naturally amplifies and then dissipates energy at its resonant frequency, creating deep attenuation notches at the harmonic frequency without requiring complex multi-stage filtering structures.

Inventive Principle:

Principle #18Mechanical vibration

2Object-affected harmful factors

If standard EMC filter components are used, then adequate attenuation of the second harmonic at 170 kHz cannot be achieved, but increasing filter dimensions and component count is necessary

Engineering Contradiction:

Improvesecond harmonic attenuationVSAvoidfilter dimensions

Core Design Contradiction:

Object-affected harmful factorsVSLength of stationary object

Solution Approach 1:

The patent changes the resonant frequency parameter of the LC circuit to match the second harmonic frequency (170 kHz). By tuning the resonant circuit to resonate at the specific harmonic frequency, the filter achieves targeted attenuation of the second harmonic without requiring multiple filter stages, thus reducing component count while improving longwave band filtering performance.

Inventive Principle:

Principle #35Parameter changes

3Object-affected harmful factors

If multiple LC filter stages are used, then adequate filtering can be achieved, but the component count and dimensions increase significantly

Engineering Contradiction:

Improveharmonic filtering performanceVSAvoidnumber of capacitors and inductances

Core Design Contradiction:

Object-affected harmful factorsVSQuantity of substance

Solution Approach 1:

The patent changes the resonant frequency parameter of the LC circuit to match the second harmonic frequency (170 kHz). By tuning the resonant circuit to resonate at the specific harmonic frequency, the filter achieves targeted attenuation of the second harmonic without requiring multiple filter stages, thus reducing component count while improving longwave band filtering performance.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent extracts and addresses only the specific problem of second harmonic attenuation at 170 kHz using a targeted resonant LC circuit, rather than implementing comprehensive multi-stage filtering for all harmonics. This selective approach removes unnecessary components while solving the critical longwave band filtering issue.

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

The filter component effectively attenuates the second harmonic, providing a low-noise signal with small dimensions, improving signal quality beyond the second harmonic frequency.

Implementation Method 1

The resonant circuit is designed and arranged for attenuation of harmonics in the longwave band... The resonant circuit is designed and set up for attenuation of a frequency of 170 kHz. Preferably, the resonant frequency of the resonant circuit is 170 kHz.

Methodology Applied

Scientific EffectResonance: Resonance

Data Source

PatentUS11258348B2EMC filter and use thereof

Publication Date: 2022.02.22 TDK ELECTRONICS AG

AI summary

A filter component such as an EMC filter and a method for using an filter component are disclosed. In an embodiment, a filter component includes a resonant circuit having an inductance and at least one capacitor that is connected in series with the inductance, wherein the resonant circuit is designed and arranged for attenuating harmonics in a longwave band.