Single-Cable RF Heating Arrangement With Filtered Signal Separation

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Solution Overview

Problem

Conventional microwave oven systems face inefficiencies due to performance degradation over time and limited energy penetration, leading to slower and less even heating of loads, while existing RF heating systems require multiple cables for signal and control communication, which is inconvenient and prone to electromagnetic interference.

Innovation Solution

The RF heating system employs a solid-state RF signal source generating low-frequency RF energy (1 MHz-300 MHz) for deeper energy penetration and includes a single cable solution for communication between the power amplifier module and smart tuning unit, using filter components to modulate and demodulate signals, reducing the need for separate cables and minimizing electromagnetic interference.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If multiple separate cables are used for RF energy and control signals, then functional separation is achieved, but device complexity and electromagnetic interference increase

Engineering Contradiction:
Improvesignal communication reliabilityVSAvoidcable arrangement complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent combines multiple separate cables (RF energy cable and control signal cable) into a single integrated cable that carries both RF energy and control signals. This merging approach reduces the number of cables and connections required, simplifying the overall system architecture while maintaining reliable communication between the power amplifier module and smart tuning unit.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The single cable is designed to perform multiple functions simultaneously: it serves as both an RF energy transmission medium and a control signal communication channel. This multi-functionality eliminates the need for separate dedicated cables for each function, reducing system complexity and the number of connection points.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Reliability

If multiple separate cables are used for RF energy and control signals, then signal separation is maintained, but electromagnetic interference increases

Engineering Contradiction:
Improvesignal transmission stabilityVSAvoidelectromagnetic interference
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent introduces filter components as intermediary elements within the single cable system. These filters act as mediators that separate and isolate different signal types (RF energy and control signals) while they coexist in the same cable, preventing electromagnetic interference between them. The filters ensure stable signal transmission by blocking unwanted frequencies and signals.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Ease of manufacture

If conventional microwave frequency RF energy is used, then system design is simplified, but energy penetration and heating effectiveness decrease

Engineering Contradiction:
Improvesystem design simplicityVSAvoidheating speed and effectiveness
Core Design Contradiction:
Ease of manufactureVSProductivity

Solution Approach 1:

The patent changes the frequency parameter of the RF energy from conventional microwave frequencies to lower frequency ranges. This parameter change enables deeper energy penetration into the load, improving heating effectiveness and productivity. The lower frequency RF energy can penetrate materials more deeply while still achieving efficient heating, resolving the contradiction between design simplicity and heating performance.

Inventive Principle:
Principle #35Parameter changes

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 approach results in faster, more even heating with reduced heating time and improved system efficiency, while simplifying the manufacturing and installation process by eliminating the complexity of multiple cables and minimizing electromagnetic interference.

Implementation Method 1

a solid-state RF signal source generating low-frequency RF energy (1 MHz-300 MHz) for deeper energy penetration

Methodology Applied
Scientific EffectElectromagnetic energy penetration: Electromagnetic Induction

Implementation Method 2

using filter components to modulate and demodulate signals

Methodology Applied
Scientific EffectSignal modulation and demodulation: Phase Modulation

Data Source

PatentEP3972386B1Cable arrangement for heating system
Publication Date: 2024.11.06 NXP USA INC
  • EP3972386B1 patent drawingFigure 1
  • EP3972386B1 patent drawingFigure 2A
  • EP3972386B1 patent drawingFigure 2B

AI summary

A system includes an RF signal source configured to output an RF signal at a first frequency, and a first controller configured to generate a first data signal encoding instructions at a second frequency. A first filter is coupled to the RF signal source. The first filter is a low pass filter having a cutoff frequency between the first frequency and the second frequency. The first filter is configured to couple to a first end of a cable. A second filter is coupled to the first controller. The second filter is a high pass filter having a cutoff frequency between the first frequency and the second frequency. The second filter is configured to couple to the first end of the cable. The system includes an impedance matching network configured to couple to a second end of the cable. A first electrode is coupled to the impedance matching network.