Yasufumi Kawai

A Drive-by-Microwave isolated gate driver with a high-speed voltage monitoring

A new isolated Drive-by-Microwave (DBM) gate driver with a high-speed voltage monitoring for over current detection is proposed, which is composed of a 2.4GHz GaN/Si DBM transmitter, DBM receiver chip and compact isolated couplers in a low-cost printed circuit board. The fabricated DBM gate driver demonstrates a 200 Mbps isolated data transmission and a GaN power switching devices driving with a turn-on skew rate of 4.2kV/us. Furthermore, it successfully detects the isolated 1.0Mbps monitoring signal at the secondary side without any isolated voltage source by means of detecting the 2.4GHz return power changing that results from the impedance miss matching of the varicap diode at a receiver.

A high-efficient driving isolated Drive-by-Microwave half-bridge gate driver for a GaN inverter

A compact isolated Drive-by-Microwave (DBM) half-bridge gate driver is newly developed, which can drive GaN-GITs with its constant and low power consumption of 0.9 W even a high switching frequency up to 1.0 MHz due to the gate power time sharing by using the 2.4GHz microwave wireless power transmission. The fabricated GaN isolated DBM half-bridge gate driver provides enough output gate power for GaN-GITs driving under 140 °C (Ta). Moreover, the fabricated isolated power source free GaN-GIT inverter module with the isolated DBM half-bridge gate drivers successfully demonstrated a 3-phase motor drive with high power conversion efficiency by covering from its low output.

A compact Drive-by-Microwave gate driver with coupler integrated in a package

A low cost and compact isolated gate driver with Drive-by-Microwave technology is developed, which consists of 2.4 GHz GaN/Si transmitter and receiver chips and the butterfly isolation coupler that integrated in a printed circuit board based package. The fabricated DBM gate driver successfully demonstrated that it drove a GaN power switching device with a very fast switching. The fabricated DBM gate driver was implemented the multi-level output function, which has the potential to realize the gate voltage profile control of a power switching device for a waveform shaping. And this function can also contribute the power consumption saving of the gate driver itself by low power output at on-state and off-state other than turn-on and turn-off.

A Drive-by-Microwave isolated gate driver with gate current charge for IGBTs

A new Drive-by-Microwave (DBM) isolated gate driver with gate current charge is presented, which drives an IGBT without an isolated power supply by switching the charged current through a microwave wireless power transmission. The fabricated compact DBM gate driver outputs an isolated gate voltage of 15V and successfully demonstrated the 300A-IGBT drive with the 2.0A peak gate current. Furthermore, the fabricated DBM gate driver realizes a 100V and 5.0MHz high-speed switching of a GaN power device without photo couplers and bulky transformers.

A1W power consumption GaN-based isolated gate driver for a 1.0 MHz GaN power system

Fast switching operation of power electronics systems is significantly advantageous for reducing volume of passive components and increasing power density in the systems. Next generation power devices, such as GaN gate-injection transistor (GIT), are promising for high frequency operations and isolated gate driving is also highly recommended owing to its noise robustness. In this paper, we propose a GaN Hetero Junction Field-Effect Transistor (HFET)-based isolated gate driver for GaN power devices with Drive-by-Microwave (DBM) technology, which can provide very compact GaN-GIT power systems owing to a gate driving by a wireless power transfer without an additional isolated voltage source. The proposed DBM gate driver can drive GaN-GIT power devices at a high switching frequency of 3 MHz with relatively low power consumption (∼1 W) and provides a short propagation delay less than 20 nsec.

A compact GaN Bi-directional switching diode with a GaN Bi-directional power switch and an Isolated gate driver

A compact and fast GaN bi-directional switching diode is described, which is integrated with a GaN/Si bi-directional power switch and a Drive-by-Microwave (DBM) isolated gate driver using a microwave wireless power transfer. The fabricated 600V 15A GaN bi-directional switching diode exhibits its low Ron of 160 mΩ under 85 °C ambient temperature without an external heat sink. The compact 12mm × 25.5mm × 3mm module also has a cooling pad to directly release heat from the GaN bi-directional power switch. By the fabricated module, the 1.0 MHz fast current direction switching was successfully realized with constant low power consumption of 0.8W thank to a gate power sharing technic by the DBM gate driver.

A compact isolated gate driver using GaN HFETs on sapphire substrate integrated with a 5.8GHz electro-magnetic resonant coupler

In this work, we developed a compact single-chip isolated gate driver with a high isolation voltage that requires no additional isolated voltage source. This developed gate driver employed “Drive-By-Microwave Technology,” which supplies an isolated signal and power by mixture to a power switching device by using wireless power transmission technology. It was also developed that a new compact butterfly-shaped electro-magnetic resonant coupler (EMRC) that can be integrated in the GaN HFETs gate driver chip. The fabricated single-chip isolated gate driver demonstrated the isolated direct driving of a GaN-GIT power switching device.