COOK Modulation for Simultaneous Wireless Power and Data Transfer
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Solution Overview
Problem
Implantable medical devices face challenges in achieving high data rate and low power consumption for wireless power and data transmission due to limited space and power constraints, with existing modulation schemes like Load Shift Keying (LSK) trading off power transfer efficiency with data rate, and requiring complex circuitry for higher RF bands.
Innovation Solution
The implementation of a novel synchronous cyclic on-off keying (COOK) modulation scheme that allows simultaneous transmission of power and data over a single inductive link, using a multi-phase phase-locked loop to control timing and retain energy in the LC tank, enabling high data rates with low power consumption by closing the switch for data transmission and opening it for power transfer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If Load Shift Keying (LSK) modulation scheme is used for power transfer, then power transfer efficiency is improved, but data rate is limited
Solution Approach 1:
The patent applies periodic action by using cyclic on-off keying modulation where the switch is periodically closed and opened. The switch is closed for N cycles to transfer data and opened for M cycles to transfer power, creating a periodic pattern that alternates between data transmission and power transfer modes. This periodic switching enables the system to achieve both high data rates during closed phases and high power transfer efficiency during open phases, resolving the contradiction between data rate and power efficiency.
2Productivity
If switch is closed for data transmission, then data rate is improved, but power transfer efficiency deteriorates
Solution Approach 1:
The patent implements periodic action through cyclic on-off keying where the switch operates in periodic cycles: closed for N cycles during data transmission phase, then opened for M cycles during power transfer phase. This periodic switching pattern allows the system to alternate between optimizing for data rate (switch closed) and optimizing for power efficiency (switch open), thereby resolving the contradiction between these two opposing requirements.
Solution Approach 2:
The patent applies dynamics by making the switch state dynamic rather than static. The switch transitions between closed and open states based on the operational phase (data transmission or power transfer), allowing the system to adapt its configuration optimally for each function. This dynamic switching enables the system to achieve high performance in both data transmission and power transfer modes sequentially.
3Productivity
If higher RF bands are used for data transmission, then data rate is improved, but device complexity increases
Solution Approach 1:
The patent applies copying by using the existing inductive power transfer link to carry both power and data signals, rather than creating separate high-frequency RF communication hardware. The data is encoded by modulating the load on the existing power transfer coil through cyclic on-off keying, effectively copying the data transmission function onto the power transfer infrastructure. This approach achieves high data rates without requiring complex additional circuitry for higher RF bands.
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 achieves broadband data transmission at half the carrier frequency with efficient power transfer, minimizing power losses and avoiding heating, while maintaining high quality factor for resonant power transfer, thus enhancing energy efficiency and performance in size and power-constrained environments.
Implementation Method 1
a resonant inductive link comprising a primary LC tank and secondary LC tank configured to resonate at a carrier frequency comprising a plurality of cycles
Implementation Method 2
primary LC tank and secondary LC tank configured to resonate at a carrier frequency comprising a plurality of cycles
Data Source
AI summary
A telemetry device includes a resonant inductive link with a primary LC tank and secondary LC tank configured to resonate at a carrier frequency. A modulator assembly in communication with the secondary LC tank implements data-synchronized cyclic on-off keying modulation (COOK) to periodically create a short across the secondary LC tank in response to a pulse from a phase selector and phase-locked loop. During the full cycle-length of the short, data can be transmitted across the inductive link while the charge across the secondary LC tank is preserved. Power may be transferred across the link during non-shorted cycles.