Kun Bao

Printable and Conformal Strongly Coupled Magnetic Resonant systems for wireless powering

In this paper, a printable compact Conformal Strongly Coupled Magnetic Resonance (CSCMR) method for wireless powering is proposed. This new wireless power transfer method uses printed planar transmitter and receiver configurations on substrates to shrink the volume down to λ0/66. Also, self-resonant spirals, which do not need lumped capacitors to achieve resonance, are designed for our novel CSCMR systems. This simplifies the fabrication process of SCMR systems and repeatable designs can be easily achieved. The efficiency of our proposed methods is validated using measurements and simulations. Our proposed designs can be incorporated easily on PCBs and added onto modern handheld devices.

Conformal SCMR system with Multiple Resonators

Wireless power transfer via Multiple Resonators in Conformal Strongly Coupled Magnetic Resonance (CSCMR) method is presented and studied in this paper. Instead of using a single loop for resonator (as done in traditional SCMR), an optimal design with multiple-loops is introduced. The proposed design achieves lower operating frequency (30% lower than the frequency of same size standard CSCMR), extended wireless power transfer (WPT) range (20% additional range) and higher WPT efficiency.

Design considerations of conformal SCMR system

Strongly Coupled Magnetic Resonance (SCMR) is an advanced technology for varied applications such as sensor networks and wearable devices. Specific applications require specific design. Two design considerations using Conformal Strongly Coupled Magnetic Resonance (CSCMR) method are presented and studied in this paper. The 1st section describes the misalignment property of CSCMR systems; the 2nd section presents the property of a CSCMR system with transmitter and receiver size.

Compact conformai strongly coupled magnetic resonant devices for medical applications

In this paper the mid-range power transfer method of conformai strongly coupled magnetic resonance is used to achieve efficient wireless power transfer with compact receiving elements. A procedure is outlined to design power transfer systems at specific frequencies using a multilayer and coplanar configuration. The proposed design operates in the medical ISM frequency of 40.68 MHz, is capable of efficiently delivering power for up to six times the radius of the compact receiving element, and exhibits increased performance with a significantly reduced volume over traditional power transfer methods.

Wireless charging for Li-Ion battery using a printable Conformal SCMR

A wireless charging system for a lithium-ion (Li-Ion) rechargeable battery using printable Conformal Strongly Coupled Magnetic Resonance (CSCMR) is proposed. This charging system could be used for implantable devices or small portable electronic devices. The charging circuit consists of the transmitter (TX) and receiver (RX) elements along with the RF-to-DC bridge rectifier and a LTC4070 designed on a PCB. It takes 18 minutes to charge a coin cell Li-Ion battery.

Applications of using conformal SCMR system for batteryless wearable sensor device

Two wearable sensor applications by using Conformal Strongly Coupled Magnetic Resonance (SCMR) wireless power transfer (WPT) system is presented. SCMR system was used to replace the battery system in these wearable sensors. The advantage of removing battery system with a WPT system is presented. Design of different shape SCMR transmitter/receiver is also discussed and demonstrated in this paper.

Efficiency analysis of a conformal SCMR system for wearable devices

The human body will be used to conduct measurements of efficiency in a wireless power transfer (WPT) system using Conformal Strongly Coupled Magnetic Resonance (SCMR). The test points for the human body are shown in figure. 2b below. We will analyze the SCMR systems response to different parts of the body and the impact they have on the efficiency of operation. Our analysis is conducted through accurate simulations and validated through physical implementation.

Multi-device wireless charging based on misalignment insensitive of conformal strongly coupled magnetic resonant system

In this paper, the misalignment property of the Conformal Strongly Coupled Magnetic Resonant (CSCMR) system is studied and applied to power multi-device simultaneously. A planar CSCMR WPT system shows excellent misalignment in azimuth plane compared to traditional SCMR system. The Receiving (RX) resonator can be moved around the Transmitting (TX) resonator in the same plane without scarifying efficiency. Using the misalignment insensitive property, a CSCMR WPT system with one transmitter and multiple receivers in the same plane or out of the plane is realized and all the receivers are successfully charged simultaneously.

Miniaturized wireless power transfer systems using 3-D strongly coupled magnetic resonance

In this paper, a novel method using 3-D Strongly Coupled Magnetic Resonance (SCMR) is proposed in order to miniaturize Wireless Power Transfer (WPT) systems. This method successfully tuned the operating frequency to lower frequencies with excellent efficiencies, thereby reducing the size of SCMR systems. Also, 3-D SCMR systems based on two and three layered spiral resonators in opposite directions shift the working frequency to lower frequency efficiently, from 210 MHz to 162 MHz and 127 MHz, respectively.

Tunable UHF origami spring antenna with actuation system

A tunable UHF origami paper based antenna is presented in this paper. The antenna is built based on the origami spring structure which can be physically adjusted. The reflection coefficient, gain and polarization of this antenna are investigated over a wide frequency band. The radiation patterns of this antenna are also examined. The proposed design of the antenna is verified by both simulations and measurements with a fabricated prototype. An actuation system is designed, which can change the total height of the antenna from 60 mm to 145 mm.