Adaptive Baseline Correction for ASK Demodulation

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Solution Overview

Problem

Incorporating data transmission capabilities into wireless power transceivers, such as those in smartphones, is challenging due to space constraints and the high cost of digital memory and filters required for demodulating amplitude shift keying (ASK) signals, which are typically used for data reception.

Innovation Solution

A wireless power transceiver design that includes a transceiver coil, a controlled switching bridge circuit, an analog voltage differential sensing circuit, an analog-to-digital converter, a compensation circuit, an accumulator, and a filter, which together enable efficient demodulation of ASK signals by sensing voltage differences and compensating for baseline drift, thereby reducing space and cost requirements.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If typical hardware for demodulating data received via ASK is used, then data transmission capability is achieved, but device space consumption increases

Engineering Contradiction:
Improvedata transmission capabilityVSAvoiddevice space
Core Design Contradiction:
Adaptability or versatilityVSArea of stationary object

Solution Approach 1:

The patent extracts and eliminates the need for complex digital memory and digital filter components from the ASK demodulation system. By using an analog front-end approach with a simple low-pass filter and threshold detector, the design removes bulky digital processing hardware while maintaining data transmission capability, thereby reducing device space consumption.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent replaces complex digital signal processing systems with analog signal processing techniques. The ASK demodulation is achieved through analog circuitry including an analog multiplier, low-pass filter, and threshold detector, eliminating the need for digital memories and digital filters that would consume significant space in mobile devices.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Adaptability or versatility

If typical hardware for demodulating data received via ASK is used, then data transmission capability is achieved, but manufacturing cost increases

Engineering Contradiction:
Improvedata transmission capabilityVSAvoidmanufacturing cost
Core Design Contradiction:
Adaptability or versatilityVSEase of manufacture

Solution Approach 1:

The patent employs simple, low-cost analog components instead of expensive digital memory and filter hardware. The demodulation system uses readily available analog circuit elements such as resistors, capacitors, operational amplifiers, and simple filters, which are significantly cheaper to manufacture and integrate than digital processing components, thereby reducing overall manufacturing cost.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

Solution Approach 2:

The patent removes expensive digital memory and digital filter components from the ASK demodulation system. By using an analog front-end approach with minimal processing requirements, the design eliminates high-cost components while maintaining functional capability, thus reducing manufacturing cost.

Inventive Principle:
Principle #2Taking out (Extraction)

3Productivity

If digital memories and digital filters are used for ASK demodulation, then data processing capability is improved, but device cost increases

Engineering Contradiction:
Improvedata processing capabilityVSAvoiddevice cost
Core Design Contradiction:
ProductivityVSEase of manufacture

Solution Approach 1:

The patent replaces digital signal processing systems with analog signal processing techniques. The ASK demodulation is achieved through analog circuitry including an analog multiplier, low-pass filter, and threshold detector, eliminating the need for digital memories and digital filters that would increase device cost while maintaining adequate data processing capability for wireless power transmission control.

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 solution allows for effective demodulation of ASK signals within limited space and cost constraints, maintaining accurate data transmission while minimizing the risk of overflow due to baseline drift, thus enhancing the functionality of wireless power transceivers.

Implementation Method 1

a transmitter formed by a transmission coil driven by time varying electric power from a power source to form a time-varying electric field

Methodology Applied
Scientific EffectElectromagnetic field generation: Electromagnetic Induction

Implementation Method 2

a receiver formed by a receiver coil in which the time-varying electric field induces an AC current

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Data Source

PatentEP3923483A1Adaptive baseline correction for delta amplification
Publication Date: 2021.12.15 STMICROELECTRONICS ASIA PACIFIC PTE
  • EP3923483A1 patent drawingFigure 1~3
  • EP3923483A1 patent drawingFigure 4~5
  • EP3923483A1 patent drawingFigure 6~7

AI summary

A data demodulating circuit includes a sensing circuit sensing a power signal applied to a coil at first and second times, and outputting an analog value representing a difference in voltage of the power signal at the first and second times. An analog-to-digital converter digitizes the analog value output by the analog voltage differential sensing circuit to produce a digital code. A compensation circuit, over a period of time, compares a present value of the digital code to a first value of the digital code during the period, and subtracts a given value from the present value of the digital code if the present value is greater than the first value but add the given value to the present value of the digital code if the present value is less than the first value. An accumulator accumulates output of the compensation circuit, and a filter filters output of the accumulator.