Intermediate Passive Loop Coil Layout for Longer-Range Wireless Power
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing wireless power transfer (WPT) systems using inductive coupling have limited range, typically requiring devices to be placed less than an inch apart, which restricts practical applications such as wireless charging of devices at a distance.
Innovation Solution
The implementation of an intermediate passive wireless loop coil system, where two coils are connected in series or parallel, with one end placed on the transmitter coil and the other end on the receiver coil, allowing for a larger separation distance between the transmitter and receiver coils.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If inductive coupling systems use planar spiral coil based design with coils placed close together, then power transfer efficiency is improved, but transfer distance is limited to less than one inch
Solution Approach 1:
The system divides the power transfer path into multiple segments by introducing intermediate passive loop coils between the active transmitter and receiver coils. These intermediate coils segment the magnetic coupling path, allowing each segment to operate at optimal coupling distance while achieving overall extended range. The transmitter coil couples to the first intermediate coil, which couples to the second intermediate coil, and so on, until the final receiver coil is reached.
Solution Approach 2:
Passive loop coils are introduced as intermediary elements that mediate the magnetic coupling between the active transmitter and receiver coils. These passive coils do not require active power electronics but serve as magnetic flux conduits, transferring energy through inductive coupling while extending the overall transfer distance. The passive coils are strategically positioned to bridge the gap between transmitter and receiver.
2Length of moving object
If multiple intermediate passive loop coils are connected in series to extend range, then transfer distance is improved, but device complexity increases
Solution Approach 1:
The passive loop coils are designed to be self-configuring through magnetic field interaction. When the active transmitter coil is energized, it automatically induces currents in the passive loop coils, which in turn induce currents in subsequent passive coils and finally in the receiver coil. This self-organizing magnetic coupling chain eliminates the need for complex control electronics, synchronization mechanisms, or active power management for each intermediate stage.
Solution Approach 2:
The passive loop coils are implemented as simple, low-cost structures without expensive active electronics, complex PCBs, or sophisticated control circuits. Each passive coil is essentially a simple conductive loop that can be manufactured using inexpensive materials and techniques, making the overall system cost-effective despite having multiple stages.
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 solution effectively extends the range of wireless power transfer beyond the traditional inch-scale limit, enabling efficient power transfer over distances of up to 10 inches or more, while maintaining reasonable efficiency.
Implementation Method 1
Inductive coupling is one of the most common types of WPT. The inductive coupling systems typically work in the kilohertz band are also usually tuned to resonance by using external capacitors
Implementation Method 2
By implementing the PSC, both the Tx and the Rx side coil can gain thin profile. Because of the spiral structure, the magnetic flux is concentrated on the center of the structure. To minimize the effect of leakage flux, the Rx coil is placed coaxially with respect to the Tx coil.
Implementation Method 3
The inductive coupling systems typically work in the kilohertz band are also usually tuned to resonance by using external capacitors
Data Source
AI summary
An intermediate passive wireless loop circuit includes one or more first loop coils, one or more second loop coils, and a set of interconnecting wires that series or parallel connect the one or more first loop coils to the one or more second loop coils such that the one or more first loop coils are separated from the one or more second loop coils by a distance.