Inductive Coupler Substrate for RF Signal Leakage Cancellation

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Solution Overview

Problem

Existing RF filters face challenges with signal leakage, which affects communication device performance in congested transmission mediums.

Innovation Solution

A substrate with an inductive coupler is introduced, featuring a first inductor coupled to a transmitter filter and antenna, and a second inductor coupled to the transmitter filter and ground. The second inductor provides a path to ground for rejected signals, generating an induced signal that counteracts leakage signals.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If traditional RF filters are used to isolate signals in congested transmission mediums, then signal isolation is achieved, but signal leakage occurs affecting communication quality

Engineering Contradiction:

Improvesignal isolationVSAvoidsignal leakage

Core Design Contradiction:

ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent converts the rejected signal (harmful factor) into a useful component by using it to generate a counteracting induced signal through magnetic coupling. The rejected signal at frequency f2 that would normally cause leakage is instead utilized to create an opposing signal that cancels out the leakage, transforming the harmful effect into a beneficial cancellation mechanism

Inventive Principle:

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

Solution Approach 2:

The patent applies preliminary anti-action by generating a counteracting induced signal before the leakage signal can propagate. The inductive coupler creates an opposing magnetic field that preemptively neutralizes the leakage signal, preventing it from affecting the receiver rather than attempting to block it after generation

Inventive Principle:

Principle #9Preliminary anti-action

2Reliability

If filters are added to improve signal isolation, then communication quality improves, but device complexity increases

Engineering Contradiction:

Improvecommunication qualityVSAvoidfilter structure

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent introduces an inductive coupler as an intermediary component between the transmitter filter and antenna. This coupler mediates the signal path by providing magnetic coupling that enables the rejection signal to generate a counteracting induced signal, improving isolation without requiring additional complex filter structures

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent replaces traditional electrical filter mechanisms with a magnetic field-based inductive coupling system. Instead of using additional electrical filters to achieve isolation, the system uses magnetic coupling between inductors to generate counteracting signals, substituting electromagnetic induction for conventional filtering approaches

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

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 inductive coupler effectively reduces signal leakage by generating an induced signal that offsets leakage signals, thereby improving isolation between transmission and receiving signals.

Implementation Method 1

The second inductor is configured such that the rejected signal traveling through the second inductor causes the first inductor to generate an induced signal that counteracts a leakage signal traveling through the transmission filter

Methodology Applied

Scientific EffectElectromagnetic induction: Electromagnetic Induction

Data Source

PatentUS12334252B2Substrate comprising an inductive coupler for signal leakage reduction

Publication Date: 2025.06.17 QUALCOMM INC

AI summary

A substrate that includes at least one dielectric layer and an inductive coupler formed in the at least one dielectric layer. The inductive coupler includes a first inductor and a second inductor. The first inductor is formed in the at least one dielectric layer. The first inductor is configured to be electrically coupled to a transmitter filter and an antenna. The second inductor is formed in the at least one dielectric layer. The second inductor is configured to be electrically coupled to the transmitter filter and ground. The second inductor is configured to provide a path to ground for a rejected signal having a rejected frequency. The second inductor is configured such that the rejected signal traveling through the second inductor causes the first inductor to generate an induced signal that counteracts a leakage signal traveling through the transmission filter.