The Experts below are selected from a list of 117 Experts worldwide ranked by ideXlab platform
Ulrike Wallrabe - One of the best experts on this subject based on the ideXlab platform.
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Comprehensive Modeling of Magnetoinductive Wave Devices for Wireless Power Transfer
IEEE Transactions on Power Electronics, 2018Co-Authors: Fralett Suarez Sandoval, Ali Moazenzadeh, Ulrike WallrabeAbstract:This work presents an analytic model based on the Impedance matrix that can predict the transferred energy to a movable receiver device in the near field of a magnetoinductive wave transmitter array. The formulas we present apply to any resonator geometry that can be described as a set of horizontal and vertical segments. The model accurately describes the system efficiency with respect to the operating frequency and to less constraining spatial configurations of the receiver device. The formulated expressions can be easily applied to distinct wireless power transfer system configurations, such as a single pair or an array of resonators, regardless their configuration. We demonstrate that the spatial resolution of the efficiency calculation is limited when only the first coupling order between the receiver and the transmitter array is considered. However, high resolution is possible when first and second coupling orders are included. Additionally, we show that the model foresees the Terminating Impedance modulation schemes that we applied only after evaluation of data obtained experimentally. These modulation schemes prevent the receiver from standing above a power null resulting from the interaction of forward and backward traveling waves, one of the major challenges in traveling wave based wireless power transfer devices.
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Nulls-Free Wireless Power Transfer With Straightforward Control of Magnetoinductive Waves
IEEE Transactions on Microwave Theory and Techniques, 2017Co-Authors: Fralett Suarez Sandoval, Saraí M. Torres Delgado, Ali Moazenzadeh, Ulrike WallrabeAbstract:We present a straightforward and yet, effective method to modulate the termination Impedance of 1-D $LC$ resonating arrays for wireless power applications. The modulation method is based on activating/deactivating the last two cells of the array allowing to remove the power nulls caused by standing waves inside this type of arrays. The modulation of the Terminating Impedances is done at a distinct frequency than the resonance frequency of the cells. We explain why and how this distinct frequency was chosen. We further demonstrate how the same modulation is applicable for a wide range of load resistances on the receiver device. Modulation is achieved by wirelessly sensing the voltage delivered by the power supply according to where above the array a receiver device is located. A microcontroller records these voltages and determines which Terminating Impedance will provide the highest possible efficiency to the receiver device. Changes in the Terminating Impedances are set by digitally controlled solid state relays. The proposed modulation method permitted to power up a receiver device with a system efficiency of up to 60% anywhere over the 30 cm length of the resonating array.
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Double-spiral coils and live Impedance modulation for efficient wireless power transfer via magnetoinductive waves
2016 IEEE Wireless Power Transfer Conference (WPTC), 2016Co-Authors: Fralett Suarez Sandoval, Saraí M. Torres Delgado, Ali Moazenzadeh, Ulrike WallrabeAbstract:We present the design and fabrication of a double-spiral coil used as the inductive element of a two-layer coupled resonator array for wireless power transfer applications. The waveguide presents an in-plane coupling coefficient of 0.92 and LC resonators with Q-factors of 97 at 13.56 MHz. Wireless monitoring of the power supply voltage enabled live modulation of the Terminating Impedance in the array. With load modulation and the low attenuation of our device we demonstrate how to power-up a receiver device with a system efficiency of nearly 60% anywhere over the 30 cm length of our resonating array.
Fralett Suarez Sandoval - One of the best experts on this subject based on the ideXlab platform.
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Comprehensive Modeling of Magnetoinductive Wave Devices for Wireless Power Transfer
IEEE Transactions on Power Electronics, 2018Co-Authors: Fralett Suarez Sandoval, Ali Moazenzadeh, Ulrike WallrabeAbstract:This work presents an analytic model based on the Impedance matrix that can predict the transferred energy to a movable receiver device in the near field of a magnetoinductive wave transmitter array. The formulas we present apply to any resonator geometry that can be described as a set of horizontal and vertical segments. The model accurately describes the system efficiency with respect to the operating frequency and to less constraining spatial configurations of the receiver device. The formulated expressions can be easily applied to distinct wireless power transfer system configurations, such as a single pair or an array of resonators, regardless their configuration. We demonstrate that the spatial resolution of the efficiency calculation is limited when only the first coupling order between the receiver and the transmitter array is considered. However, high resolution is possible when first and second coupling orders are included. Additionally, we show that the model foresees the Terminating Impedance modulation schemes that we applied only after evaluation of data obtained experimentally. These modulation schemes prevent the receiver from standing above a power null resulting from the interaction of forward and backward traveling waves, one of the major challenges in traveling wave based wireless power transfer devices.
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Nulls-Free Wireless Power Transfer With Straightforward Control of Magnetoinductive Waves
IEEE Transactions on Microwave Theory and Techniques, 2017Co-Authors: Fralett Suarez Sandoval, Saraí M. Torres Delgado, Ali Moazenzadeh, Ulrike WallrabeAbstract:We present a straightforward and yet, effective method to modulate the termination Impedance of 1-D $LC$ resonating arrays for wireless power applications. The modulation method is based on activating/deactivating the last two cells of the array allowing to remove the power nulls caused by standing waves inside this type of arrays. The modulation of the Terminating Impedances is done at a distinct frequency than the resonance frequency of the cells. We explain why and how this distinct frequency was chosen. We further demonstrate how the same modulation is applicable for a wide range of load resistances on the receiver device. Modulation is achieved by wirelessly sensing the voltage delivered by the power supply according to where above the array a receiver device is located. A microcontroller records these voltages and determines which Terminating Impedance will provide the highest possible efficiency to the receiver device. Changes in the Terminating Impedances are set by digitally controlled solid state relays. The proposed modulation method permitted to power up a receiver device with a system efficiency of up to 60% anywhere over the 30 cm length of the resonating array.
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Double-spiral coils and live Impedance modulation for efficient wireless power transfer via magnetoinductive waves
2016 IEEE Wireless Power Transfer Conference (WPTC), 2016Co-Authors: Fralett Suarez Sandoval, Saraí M. Torres Delgado, Ali Moazenzadeh, Ulrike WallrabeAbstract:We present the design and fabrication of a double-spiral coil used as the inductive element of a two-layer coupled resonator array for wireless power transfer applications. The waveguide presents an in-plane coupling coefficient of 0.92 and LC resonators with Q-factors of 97 at 13.56 MHz. Wireless monitoring of the power supply voltage enabled live modulation of the Terminating Impedance in the array. With load modulation and the low attenuation of our device we demonstrate how to power-up a receiver device with a system efficiency of nearly 60% anywhere over the 30 cm length of our resonating array.
Ali Moazenzadeh - One of the best experts on this subject based on the ideXlab platform.
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Comprehensive Modeling of Magnetoinductive Wave Devices for Wireless Power Transfer
IEEE Transactions on Power Electronics, 2018Co-Authors: Fralett Suarez Sandoval, Ali Moazenzadeh, Ulrike WallrabeAbstract:This work presents an analytic model based on the Impedance matrix that can predict the transferred energy to a movable receiver device in the near field of a magnetoinductive wave transmitter array. The formulas we present apply to any resonator geometry that can be described as a set of horizontal and vertical segments. The model accurately describes the system efficiency with respect to the operating frequency and to less constraining spatial configurations of the receiver device. The formulated expressions can be easily applied to distinct wireless power transfer system configurations, such as a single pair or an array of resonators, regardless their configuration. We demonstrate that the spatial resolution of the efficiency calculation is limited when only the first coupling order between the receiver and the transmitter array is considered. However, high resolution is possible when first and second coupling orders are included. Additionally, we show that the model foresees the Terminating Impedance modulation schemes that we applied only after evaluation of data obtained experimentally. These modulation schemes prevent the receiver from standing above a power null resulting from the interaction of forward and backward traveling waves, one of the major challenges in traveling wave based wireless power transfer devices.
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Nulls-Free Wireless Power Transfer With Straightforward Control of Magnetoinductive Waves
IEEE Transactions on Microwave Theory and Techniques, 2017Co-Authors: Fralett Suarez Sandoval, Saraí M. Torres Delgado, Ali Moazenzadeh, Ulrike WallrabeAbstract:We present a straightforward and yet, effective method to modulate the termination Impedance of 1-D $LC$ resonating arrays for wireless power applications. The modulation method is based on activating/deactivating the last two cells of the array allowing to remove the power nulls caused by standing waves inside this type of arrays. The modulation of the Terminating Impedances is done at a distinct frequency than the resonance frequency of the cells. We explain why and how this distinct frequency was chosen. We further demonstrate how the same modulation is applicable for a wide range of load resistances on the receiver device. Modulation is achieved by wirelessly sensing the voltage delivered by the power supply according to where above the array a receiver device is located. A microcontroller records these voltages and determines which Terminating Impedance will provide the highest possible efficiency to the receiver device. Changes in the Terminating Impedances are set by digitally controlled solid state relays. The proposed modulation method permitted to power up a receiver device with a system efficiency of up to 60% anywhere over the 30 cm length of the resonating array.
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Double-spiral coils and live Impedance modulation for efficient wireless power transfer via magnetoinductive waves
2016 IEEE Wireless Power Transfer Conference (WPTC), 2016Co-Authors: Fralett Suarez Sandoval, Saraí M. Torres Delgado, Ali Moazenzadeh, Ulrike WallrabeAbstract:We present the design and fabrication of a double-spiral coil used as the inductive element of a two-layer coupled resonator array for wireless power transfer applications. The waveguide presents an in-plane coupling coefficient of 0.92 and LC resonators with Q-factors of 97 at 13.56 MHz. Wireless monitoring of the power supply voltage enabled live modulation of the Terminating Impedance in the array. With load modulation and the low attenuation of our device we demonstrate how to power-up a receiver device with a system efficiency of nearly 60% anywhere over the 30 cm length of our resonating array.
Milutin Stanacevic - One of the best experts on this subject based on the ideXlab platform.
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UEMCON - Study of mm-sized Coil to Coil Backscatter Based Communication Link
2019 IEEE 10th Annual Ubiquitous Computing Electronics & Mobile Communication Conference (UEMCON), 2019Co-Authors: Xiao Sha, Yasha Karimi, Samir R. Das, Petar M. Djuric, Milutin StanacevicAbstract:Distribution of a large number of mm-sized sensing units in brain is a vision for the next generation of implantable devices for neural recording. Recorded data from the implants is conventionally transferred to a central external device and the bandwidth of the uplink channel is limited by the number of the implanted units. For the first time, we demonstrate the feasibility of local communication between mm-sized coils using backscattering technique which promises to reduce the requirement on the uplink bandwidth between the external device and the implants. To demonstrate the feasibility of the proposed link, two implanted coils located at 14 mm implantation depth are used with the distance between coils of 1.5 mm. The transmitting coil switches between two Terminating Impedance and the input voltage at the receiving coil is observed in the simulations with a triple-loop inductive link designed at 90 MHz. We show that the voltage difference in the received signal for two transmitting states can be resolved by demodulator of the receiving implant demonstrating the link feasibility. Several simulations show the functionality of the link under wide range of different angular and lateral misalignment.
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Design and Evaluation of “BTTN”: A Backscattering Tag-to-Tag Network
IEEE Internet of Things Journal, 2018Co-Authors: Jihoon Ryoo, Samir R. Das, Jinghui Jian, Akshay Athalye, Milutin StanacevicAbstract:Radio frequency (RF)-powered backscatter communication between passive tags holds tremendous potential as an enabling technology for a ubiquitous “Internet of Things.” We develop a backscattering tag-to-tag network (BTTN), comprised of passive tags capable of large-scale, passive, and multihop communication with each other via backscatter modulation of an external RF excitation signal. The low sensitivity and lack of active demodulator on passive tags present significant challenges to the communication, including a unique phase cancellation problem, which significantly affects the range and robustness of a passive tag-to-tag link. We overcome these challenges using innovative tag architecture and also develop a novel multiphase backscatter modulation technique with a learning mechanism that overcomes the phase cancellation problem. This improves the link performance bringing passive tag-to-tag communication closer to practical use. The additional hardware compared to the conventional radio frequency identification tag architecture includes one more Terminating Impedance in the modulator. The data rate is reduced due to backscatter at two different phases while the increase in the power consumption is negligible. We develop prototype BTTN tag hardware and firmware and evaluate its performance. The prototype achieves link ranges of up to 3 m at 5 kb/s with an excitation power level of only -20 dBm while successfully overcoming phase cancellation. We further extend BTTN operation to a multihop network where we demonstrate a four hop link capable of communicating over 12 m under similar conditions.
Saraí M. Torres Delgado - One of the best experts on this subject based on the ideXlab platform.
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Nulls-Free Wireless Power Transfer With Straightforward Control of Magnetoinductive Waves
IEEE Transactions on Microwave Theory and Techniques, 2017Co-Authors: Fralett Suarez Sandoval, Saraí M. Torres Delgado, Ali Moazenzadeh, Ulrike WallrabeAbstract:We present a straightforward and yet, effective method to modulate the termination Impedance of 1-D $LC$ resonating arrays for wireless power applications. The modulation method is based on activating/deactivating the last two cells of the array allowing to remove the power nulls caused by standing waves inside this type of arrays. The modulation of the Terminating Impedances is done at a distinct frequency than the resonance frequency of the cells. We explain why and how this distinct frequency was chosen. We further demonstrate how the same modulation is applicable for a wide range of load resistances on the receiver device. Modulation is achieved by wirelessly sensing the voltage delivered by the power supply according to where above the array a receiver device is located. A microcontroller records these voltages and determines which Terminating Impedance will provide the highest possible efficiency to the receiver device. Changes in the Terminating Impedances are set by digitally controlled solid state relays. The proposed modulation method permitted to power up a receiver device with a system efficiency of up to 60% anywhere over the 30 cm length of the resonating array.
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Double-spiral coils and live Impedance modulation for efficient wireless power transfer via magnetoinductive waves
2016 IEEE Wireless Power Transfer Conference (WPTC), 2016Co-Authors: Fralett Suarez Sandoval, Saraí M. Torres Delgado, Ali Moazenzadeh, Ulrike WallrabeAbstract:We present the design and fabrication of a double-spiral coil used as the inductive element of a two-layer coupled resonator array for wireless power transfer applications. The waveguide presents an in-plane coupling coefficient of 0.92 and LC resonators with Q-factors of 97 at 13.56 MHz. Wireless monitoring of the power supply voltage enabled live modulation of the Terminating Impedance in the array. With load modulation and the low attenuation of our device we demonstrate how to power-up a receiver device with a system efficiency of nearly 60% anywhere over the 30 cm length of our resonating array.