MCR-WPT Printed Spiral Coils

MCR-WPT Printed Spiral Coils Prototype Circuit

Here we give a brief overview of the results and Design methodology used for the Magnetically Coupled Resonant Wireless Power Transmission (MCR-WPT) Printed Spiral Coils (PSC) designed for cellphones.

Below is a list of all the topics we cover in this page. Go ahead and click on any of these links, and you’ll be taken to that specific section.

MCR-WPT Coils suffer from reduced efficiency when their separation distance is less than the optimal distance for peak transfer efficiency, due to a phenomenon known as frequency splitting. For more information about this efficiency problem that the Maximum Peak Detection and Auto-Tuning Control Circuit is designed to overcome, click on button on the right to find out more.

DESIGN PROTOTYPE

Video showing an early test of the MCR-WPT coil prototypes.

Experimental setup for MCR-WPT-coil efficiency testing at different distances

Separation DistanceHarmonic Balance Output PowerFunction Generator Output Power
0.5in0.064 Watts0.0576 Watts
1.0in0.226 Watts0.2401 Watts
1.5in0.337 Watts0.156 Watts
Simulation vs Measurement Output Power Results (5×2.52In double layer FR4 design for cellphones)

DESIGN LAYOUT MOMENTUM

Double layer MCR-WPT coils layout design example

Double layer MCR-WPT coils layout design example

There are many things to consider when designing the MCR-WPT coils for high efficiency at a desired Self-Resonant Frequency (SRF). These considerations include the effects of changing the coil parameters such as wire width, wire spacing, coil diameter, etc.

For a brief overview of the effects of parameter changes on efficiency and the SRF, or for the final design parameter values, click on the respective button to find out more.

NOTE: The above 2D image of the 3D model does not explain much, and any additional images may make this section bloated. So a short 8 minute video is provided that shows the design, 3D model and simulation of the coils in Momentum starting at the 2:40 mark. Click the button below to go to the video.

DESIGN LAYOUT EMPRO

Double layer MCR-WPT Coils design example 3D model in EMPro

NOTE: As stated in the previous section, a 2D image of the 3D model just does not do it justice. So a short 5 minute video is provided to show the design modifications and simulation setup of the MCR-WPT coils in EMPro. Click the button below to go to the video.

DESIGN PROCESS

A two part step-by-step video walk-through was made to demonstrate this design flow using one of the final designs.
The videos are provided in the sections below for your convenience.

Step-by-step video walkthrough of the design process for the final design part 1.

Step-by-step video walkthrough of the design process for the final design part 2.