Masaya Tamura

Power station under seawater

In order to contribute to our marine resources development, our laboratory is aimed at the establishment of system that can wirelessly transfer the power to the remotely-operated vehicle under seawater. As one of the necessary technologies, there is wireless power transfer of kW power, and the use of electromagnetic fields as a solution has attracted attention. However, since nobody elucidates the electric properties of water/seawater under the circumstance of kW power yet, the structure of the electrodes used in the WPT under water is not optimized. Therefore, we are developing the method to measure them and the electrode structure suitable for WPT under water.

RF filter monuted into the portable device

Filter is an indispensable circuit for the wireless communications device. The designs of filter vary from a very small filter mounted into the portable devices to a filter with high power durability used in the base station. Those filters, however, have common challenges such as downsizing of the filter and development of the resonator with high quality factor. We are studying the techniques to solve these challenges. Furthermore, depending on various applications, we are also developing the filter with additional value such as high power durability and tunability.

[1] S. Tomida and M. Tamura, “Establishment of Design Approach for Bandpass Filter using Triple-mode Stripline Resonator,” IEEE AP/MTT-S Midland Student Express 2016 Spring, S3-3, Nagoya, April 2016.
[2] M. Tamura, T. Yang, and T. Itoh, “Very Compact and Low-profile LTCC Unbalanced-to-Balanced Filters with Hybrid Resonators,” IEEE Trans. Microwave Theory and Techniques, vol. 59, no. 8, pp. 1925-1936, Aug. 2011.
[3] M. Tamura, T. Ishizaki, and M. Hoft, “Design and Analysis of Vertical Split Ring Resonator and its Application to Unbalanced-balanced Filter,” IEEE Trans. Microwave Theory and Techniques, vol. 58, no. 1, pp. 157-164, Jan. 2010.

Battery-less wireless sensor system

For the conventional sensor system, the power supply and data transmission are done by the wiring harness, or data is wirelessly transmitted to the master by the battery. In this case, it is difficult to manage this system at the place beyond someone’s reach in an enclosed space such as inside the vehicles and high-temperature furnace at the factory. However, this problem can be solved by wireless power transfer. Therefore, we are developing the fusion modules that can wirelessly transfer the data to the master by wireless power transfer.