Dual-Drain GaN Magnetic Sensor Compatible With GaN RF Power Technology

This letter presents first–ever fabricated GaN split-current magnetic sensor device. This is the key technology needed to fully unlock the potential of GaN power technology. Device operation and key manufacturing steps are also presented. The measured relative current sensitivity is constant at 14 % T-1 for wide mT range of the magnetic field. The constant sensitivity of a fabricated sensor can be attributed to device’s 2DEG nature, i.e. its high electron concentration and mobility, and very small layer thickness

Analysis of GaN HEMTs Switching Transients Using Compact Model

The methodology to model GaN power HEMT switching transients at the circuit level is presented in this paper. A compact model to predict devices’ pulse switching characteristics and current collapse reliability issue has been developed. Parasitic RC subcircuits and a standard double-pulse switching tester to model intrinsic parasitic effects and to analyze power dissipation of GaN power HEMT are proposed and presented. Switching transient including gate-lag and drain-lag is predicted for ideal (without trap) and nonideal (with trap) devices. The results are validated by and compared to 2-D finite-element TCAD simulations. The developed methodology and compact model can successfully predict the dynamic behaviour of single and multiple power GaN HEMTs used for power electronics design

High Sensitivity Dual-Gate Four-Terminal Magnetic Sensor Compatible with SOI FinFET Technology

This letter presents a unique device concept of split-current magnetic sensor that is fully compatible with SOI FinFET technology. The fabricated dual-gate four-terminal device brings a step change in SOI integrated sensor capabilities, its measured current related relative sensitivity is as high as 3400 % T-1 at 2 μA of total supply current, comparing to the sensitivity of 3%T-1 exhibited by commercially available silicon MagFETSs. The device’s very high sensitivity is attributed to its novel current conduction phenomena and the internal magnetic deflection enhancement loop demonstrated using 3D TCAD numerical simulations. This new magnetic sensor is a very promising candidate for the next generation of magnetic sensitive smart-power integrated circuits

GaN Transistors’ Radiated Switching Noise Source Evidenced by Hall Sensor Experiments Toward Integration

Wide bandgap Gallium Nitride (GaN) technology promises to deliver the next generation of power transistors capable of high energy density and compact design integration however, without active monitoring high failing rates are recorded due to its instability to design parameter variations. Moreover, the electromagnetic (EM) radiofrequency (RF) emissions due to GaN power switching require extra design resources. Considering the extensive research area dedicated to galvanic isolated magnetic sensors for GaN wafer monolithic integration with usage in power monitoring, this study investigates the conditions that a Hall sensor is required to meet when operating in close proximity of a GaN transistor. Through considerable experimental testing, it was determined that the sensor requires a magnetic field starting from ±1 mT when interfaced with a microcontroller. Additionally, since the GaN transistor's EM RF switching noise was one of the most monitored parameters during the experiments, it was discovered that it is proportional to the transistor's current transfer area whereas its magnitude is due to electrical current required by the load. As a result of these findings, the EM radiated switching noise may apply to all electrical switches and provide a significant advantage when designing for EM compatibility (EMC)

Wireless Communication Test on 868 MHz and 2.4 GHz from inside the 18650 Li-Ion Enclosed Metal Shell

As the RF communication on 18650 Li-ion cell level has not been reported due to its challenges and constrains, in this work, a valid wireless data link is demonstrated in an enclosed empty metal shell at 868 MHz and 2.4 GHz based on the IEEE 802.15.4 standard. The experimental tests are carried out using two generic unturned radiative structures, a wire loop fitted inside a cell shell, and an open terminal sub miniature version A (SMA), subsequently oriented vertically and horizontally relative to the ground plane. Based on signal strength indicator, bit error rate, and packet error rate, the test characterized a payload of 120 bytes at the highest speed of 150 kbps and 250 kbps supported by the IEEE 802.15.4 for the two communication frequencies. A MATLAB simulation is used in parallel to determine the three-dimensional radiative pattern of the two structures, whereas a three-ray model for multipath range propagation is implemented to complete the empirical experiments. It was demonstrated through testing communication of up to 10 m for both operating frequencies, proving the concept of wireless cell communication within short ranges, an essential feature for monitoring the health of each cell inside future electric vehicles (EVs)

DC Power Line Communication (PLC) on 868 MHz and 2.4 GHz Wired RF Transceivers

Efficient management through monitoring of Li-ion batteries is critical to the progress of electro-mobility and energy storage globally, since the technology can be hazardous if pushed beyond its safety boundaries. Battery management systems (BMSs) are being actively improved to reduce size, weight, and cost while increasing their capabilities. Using power line communication, wireless monitoring, or hybrid data links are one of the most advanced research directions today. In this work, we propose the use of radio frequency (RF) transceivers as a communication unit that can deliver both wired and wireless services, through their superior analog and digital signal processing capability compared to PLC technology. To validate our approach computational simulation and empirical evaluation was conducted to examine the possibility of using RF transceivers on a direct current (DC) bus for wired BMS. A key advantage of this study is that it proposes a flexible and tested system for communication across a variety of network scenarios, where wireless data links over disrupted connections may be enabled by using this technology in short-range wired modes. This investigation demonstrates that the IEEE 802.15.4-compliant transceivers with operating frequencies of 868 MHz and 2.4 GHz can establish stable data links on a DC bus via capacitive coupling at high data rates

Time-Domain Modeling of a Distribution System to Predict Harmonic Interaction Between PV Converters

Due to the interaction converter control, pre-existing distortion and grid impedance, the harmonic levels caused by renewable energy sources (RESs) are continuously changing, and their assessment requires the use of dedicated computer models. Several time-domain models have been proposed to carry out this analysis, however, they fall short of at least one requirement: either they do not provide accurate results, or they require an excessively long simulation time. This paper presents a novel time-domain model to address the gap described above: the proposed model employs average functions and a novel switching emulator. Therefore, it is referred to as ‘average model with switching emulator’ (AMSE). The proposed model is compared with existing models, and the results indicate that the AMSE meet both requirements stated above, as it accurately represents harmonic distortion while reducing significantly the simulation time. The second part of the paper discusses mitigating solutions to harmonic amplification in systems with a high penetration of VSCs, and shows the effectiveness of using an Active Filter to reduce harmonic levels in system experiencing resonance conditions