Kyushu University Academic Staff Educational and Research Activities Database
List of Presentations
Kuniaki Yoshitomi Last modified date:2019.06.20

Professor / Education Collaboration Department / Department of I&E Visionaries / Faculty of Information Science and Electrical Engineering


Presentations
1. Mohamed Aboualalaa, Islam Mansour, Mohamed Mansour, Adel Bedair, Ahmed Allam, Mohammed Abo-Zahhad, Hala Elsadek, Kuniaki Yoshitomi, Ramesh K. Pokharel, Dual-band Rectenna Using Voltage Doubler Rectifier and Four-Section Matching Network, 2018 IEEE Wireless Power Transfer Conference (WPTC), 2018.06, A dual-frequency rectenna is introduced in this paper. An enhanced-gain antenna is integrated with the rectifying circuit for increasing the rectenna capability for scavenging. A voltage doubler circuit is used for the rectification. Moreover, a four-section matching network is employed for the matching between the antenna and the rectifier. The measured results reveal that the RF-to-DC conversion efficiency is more than 50% over wide range of the input power, from-3.5dBm to 10. 5dBm at f1 and from -4.5dBm to 11dBm at f2, with maximum conversion efficiency of 63% and 69% at input power of 7dBm and 3. 5dBm, respectively with resistive load of 1KΩ. Further-more, the measurements illustrate good agreement between the simulated and measured results..
2. M. R. Saad, Fairus Tahar, Sumin Chalise, Adel Barakat, Kuniaki Yoshitomi, Ramesh K. Pokharel, High FOM Dual Band Wireless Power Transfer using Bowtie Defected Ground Structure Resonators, 2018 IEEE Wireless Power Transfer Conference (WPTC), 2018.06, This work presents a dual-band wireless power transfer (WPT) system with high figure of merit (FoM). One band can be used for power transfer and another for data transfer in biomedical applications. A Bow-tie Defected Ground Structure (DGS) resonators with high quality (Q-) factor and coupling (k-) factor is utilized for ensuring high efficiency. An equivalent circuit model using the admittance (J-) inverters is utilized to design the admittance inversion and compensation networks. The measured result shows that the proposed WPT system is able to transfer the power at both of the bands with a high FoM, making a suitable candidate for compact near filed WPT applications..
3. Fairus Tahar, Sumin Chalise, Kuniaki Yoshitomi, Adel Barakat, Ramesh K. Pokharel, Compact Dual-Band Wireless Power Transfer Using Overlapped Single Loop Defected Ground Structure, 2018 IEEE Wireless Power Transfer Conference (WPTC), 2018.06, This paper presents a compact dual-band wireless power transfer (WPT) system using overlapped defected ground structure for biomedical applications. One band for power and another for data transfer. The proposed defected ground structure can channel two distinct resonant frequencies. As a result, the fabricated WPT device has almost 50% reduction in the size without changing other performances compared to ref. [9]. The fabricated device is 15 mm ×15 mm. The measured efficiency is 71% and 73%, respectively at 0.45 GHz and 0.95 GHz at WPT distance of 12.5mm..
4. Fairus Tahar, Sumin Chalise, Adel Barakat, Kuniaki Yoshitomi, Ramesh K. Pokharel, Dual-Band Defected Ground Structure Resonators Wireless Power Transfer System Connected to Voltage-Doubler Circuit, 2019 IEEE Topical Conference on Wireless Sensors and Sensor Networks (WiSNet), 2019.01, Recently, research on multiband wireless power transfer (WPT) systems has drawn attention high efficiency in the air with a small package of WPT size for the possible bio-related application. However, the WPT system itself is not complete without complementary circuit to convert the received RF power to DC. Thus, this paper presents a design method of integrating a predesigned dual-band WPT system to a voltage-doubler (VD) without external circuit configuration. The method proved to be working as experiment RF-DC conversion efficiency recorded to be 35.2% and 37.9% in both bands, respectively with 20 mm working distance through skin, -1.27% and -1.6% dropped from air condition..
5. Chalise, S., Tahar, F., Saad, M.R., Baraket, A., Yoshitomi, K., Pokharel, R.K., High efficiency wireless power transfer system using spiral DGS resonators through biological tissues, 2018 International Microwaves for Biomedical Conference (IMBioC), 2018.06, This paper presents a wireless power transfer (WPT) system to transfer power through the tissues using Defected Ground Structure (DGS) resonators. The proposed DGS resonator is made of a spiral structure at the ground plane to increase the quality (Q-) factor, and when two DGS resonators are coupled back to back, it transforms to a bandpass filter resulting in the wireless power transfer. Experiment on the proposed WPT system shows an efficiency of 67.7% in air and 61% when placed in the tissue environment at 20MHz frequency..
6. Aboualalaa, M., Abdel-Rahman, A.B., Allam, A., Pokharel, R.K., Yoshitomi, K., Elsadek, H., Compact 24GHz half-slot antenna for energy combining, 2018 International Applied Computational Electromagnetics Society Symposium in Denver, ACES-Denver 2018, 2018.03, A compact half-slot microstrip antenna is proposed in this paper. The antenna consists of microstrip line-fed half slot, and an open-circuited stub is connected to the microstrip feed line to adjust the matching at the operated frequency band. A half slot is used for miniaturization, as well as due to concentrating the field at only half slot; consequently, it decreases the resonance frequency and improves the antenna radiation characteristics. The antenna radiates at 24 GHz with measured fractional impedance bandwidth of 9%. The antenna gain at the resonant frequency is 5.2 dBi. The proposed antenna shows about 60% length reduction. Therefore, the proposed half slot antenna could be used for energy harvesting applications, at 24 GHz ISM band, due to its compact size with improved gain value. The proposed antenna was designed using ANSYS high-frequency structure simulator (HFSS). The simulated and measured results show good agreement..
7. El-Hameed, A.S.A., Barakat, A., Abdel-Rahman, A.B., Allam, A., Pokharel, R.K., Yoshitomi, K., Broadband printed-dipole antenna for future 5G applications and wireless communication, 2018 IEEE Radio and Wireless Symposium, RWS 2018, 2018.01.
8. Saad, M.R., Tahar, F., Barakat, A., Yoshitomi, K., Pokharel, R.K., Analysis of near field wireless power transfer using bow-tie defected ground structure, 2017 IEEE Asia-Pacific Microwave Conference Proceedings, APMC 2017, 2017.11.
9. Eu, G.C., Mansour, M., Yoshitomi, K., Kanaya, H., A printed array antenna for multi-layer PCB design, 2017 International Symposium on Antennas and Propagation, ISAP 2017, 2017.10.
10. 岩井郁也, 吉富邦明, 金谷 晴一, Miniaturized High‒band UWB Monopole Antenna, 2016 Asia‒Pacific Workshop on Fundamentals and Application of Advanced Semiconductor Devices, 2016.07.
11. 山口恭平, 吉富邦明, 金谷 晴一, Development of 5GHz Circularly Polarized Slot Antenna, 2016 Asia‒Pacific Workshop on Fundamentals and Application of Advanced Semiconductor Devices, 2016.07.
12. 古賀柾洋, 吉富邦明, 金谷 晴一, Miniaturized High Gain Slot Dipole Array Antenna for X‒band Application, 2016 Asia‒Pacific Workshop on Fundamentals and Application of Advanced Semiconductor Devices, 2016.07.
13. Hany A. Atallah, Adel B. Abdel-Rahman, 吉富邦明, POKHAREL RAMESH KUMAR, Design of Miniaturized Reconfigurable Slot Antenna Using Varactor Diodes for Cognitive Radio Systems, The Fourth International Japan-Egypt Conference on Electronics, Communications and Computers JEC-ECC 2016, 2016.05.
14. Hany A. Atallah, Adel B. Abdel-Rahman, 吉富邦明, Sherif Hekal, POKHAREL RAMESH KUMAR, Design of Frequency Tunable CPW-Fed UWB Antenna Using Varactor Diodes for Cognitive Radio and Future Software Defined Radio, IEEE Wireless and Microwave Technology Conference WAMICON 2016, 2016.04.
15. Hany A. Atallah, Adel B. Abdel-Rahman, 吉富邦明, POKHAREL RAMESH KUMAR, New Compact Tunable Filter-Antenna Using Varactor Loaded Ring Resonator for Cognitive Radio Front End System, 2016 IEEE International Conference on Wireless Information Technology and Systems (ICWITS) and Applied Computational Electromagnetics Society (ACES), 2016.03.
16. Hany A. Atallah, Adel B. Abdel-Rahman, 吉富邦明, POKHAREL RAMESH KUMAR, Compact Frequency Tunable Filtenna with Wide Continuous Tuning Range Using Capacitively Loaded Folded Arms Open Loop Resonator for Interweave Cognitive Radio Applications, 2016, 33rd NATIONAL RADIO SCIENCE CONFERENCE (NRSC 2016), 2016.02.
17. Hany A. Atallah, Adel B. Abdel-Rahman, 吉富邦明, POKHAREL RAMESH KUMAR, Novel Compact Tunable Bandpass Filter Using Capacitively Loaded H-shaped Resonator, 2015 IEEE International Conference on Electronics, Circuits, and Systems, 2015.12.
18. M Hanif, Ramesh Kumar Pokharel, 吉富邦明, Adel Barakat, Hala Elsadek, A Gain Enhanced 60 GHz CMOS Antenna-On-Chip Using Off-Chip Mu Near Zero Metamaterial Lens, 2015 IEEE 4th Asia-Pacific Conference on Antennas and Propagation, 2015.07.
19. 織田 知樹, 飯笹 直人, GUAN CHAI EU, Haruichi Kanaya, 吉富邦明, Circularly Polarized One-Sided Directional Slot Array Antenna for 920MHz Application, 2015 IEEE 4th Asia-Pacific Conference on Antennas and Propagation, 2015.07.
20. Hany A. Atallah, Adel B. Abdel-Rahman, 吉富邦明, POKHAREL RAMESH KUMAR, Mutual Coupling Reduction between Microstrip Antenna Array Elements Using CSRRs-Based DGS Bandstop Filter, The Third International Japan-Egypt Conference on Electronics, Communications and Computers、JEC-ECC 2015, 2015.03.
21. 飯笹直人, 吉富邦明, 金谷晴一, Dual Band Slot Dipole Array Antenna for Wireless LAN, 第3回バイオメカニクス研究センター&エレクトロニクス実装学会九州支部合同研究会, 2015.02.
22. 飯笹直人, 吉富邦明, POKHAREL RAMESH KUMAR, 金谷晴一, 2 x 2 Slot Dipole Array Antenna with CPW for 2.4GHz Band, 電子情報通信学会マイクロ波研究会, 2014.12.
23. POKHAREL RAMESH KUMAR, 牟田 修, JIA HONGTING, MAHDIPOUR FARHAD, GOULART FERREIRA VICTOR MAURO, 吉富邦明, 金谷晴一, Ahmed Allam, 吉田啓二, Activities on Microwave Education and Research between Japan and Egypt ~ Partnership between Kyushu University, Japan and Egypt-Japan University of Science and Technology, Egypt ~, 電子情報通信学会マイクロ波研究会, 2014.11.
24. 飯笹直人, Kuniaki Yoshitomi, Ramesh Kumar Pokharel, Haruichi Kanaya, High Gain 4 × 4 Slot Dipole Antenna Array in the 5GHz Band, 2014 Asia-Pacific Conference on Antennas and Propagation, 2014.07.
25. Hany A. Atallah, Adel B. Abdel-Rahman, 吉富邦明, POKHAREL RAMESH KUMAR, Novel Compact UWB Monopole RDRA for Cognitive Radio Spectrum Sensing Applications, 2014 IEEE Fourth International Conference on Consumer Electronics - Berlin (ICCE-Berlin), 2014.09.
26. 金谷晴一, 藤田浩司, 井地口智詞, Keiji Yoshida, 吉富邦明, Akira Ishikawa, Shugo Fukagawa, Noriyuki Kodama, Akihiro Tahira, Compact Size UWB Planer Antenna on Flexible Substrate, 2014 IEEE International Symposium on Antennas and Propagation and USNC-URSI National Radio ScienceMeeting, 2014.07.
27. A. Barakat, A. Allam, H. Elsadek, Haruichi Kanaya, Hongting Jia, Kuniaki Yoshitomi, Ramesh Kumar Pokharel, Back radiation reduction of 60 GHz CMOS slot Antenna-on-Chip (AoC) using Artificial Dielectric Layer (ADL) for Area Reuse, 2014 IEEE International Symposium on Antennas and Propagation and USNC-URSI National Radio ScienceMeeting, 2014.07.
28. Tomoya Ijiguchi, Daisuke Kanemoto, Kuniaki Yoshitomi, Keiji Yoshida, POKHAREL RAMESH KUMAR, Akira Ishikawa, Shugo Fukagawa, Noriyuki Kodama, Akihiro Tahira, Haruichi Kanaya, Development of Circularly Polarized Planar Slot Antenna for 5.8 GHz-DSRC Application, 2013 Asia-Pacific Microwave Conference , 2013.11, A novel design method of circularly polarized planar slot antenna for 5.8 GHz Dedicated Short Range Communications (DSRC) applications is proposed. For realized circularly polarized wave, we use planar slot antenna. By optimizing the lengths and widths of antenna slot, resonances can be obtained at 5.8 GHz frequency. The antenna generates a circularly polarized wave providing a slot in the two orthogonal directions. Improving the gain by providing a slot in the same direction, arrayed structure is adopted. The final antenna size is 17 mm x 15 mm x 1.6 mm. Our antenna was fabricated on the FR4 substrate and impedance bandwidth is 310 MHz from 5.62 to 5.93 GHz. Moreover circularly polarized wave can be obtained..
29. Kouji Fujita, Daisuke Kanemoto, Kuniaki Yoshitomi, Keiji Yoshida, Haruichi Kanaya, UWB Circularly Polarized Planar Antenna on Flexible Substrate, IEEE MTT-S International Microwave Workshop Series on RF and Wireless Technologies for Biomedical and Healthcare Applications (IMWS-Bio 2013), 2013.07, This paper presents the design of the circularly polarized slot antenna on the flexible substrate for ultra wide band (UWB) high band application. We applied two slots which are crossed perpendicularly to obtain circularly polarized wave. By optimizing the lengths and widths of the antenna slots and substrate, wide band impedance matching can be realized. Impedance bandwidth of proposed antenna is 5.60 GHz from 7.11 to 12.71 GHz and the antenna size is 16 mm x 16.3 mm x 0.254 mm..
30. Haruichi Kanaya, Kanemoto Daisuke, Kazuhiro Hayakawa, Keiji Yoshida, POKHAREL RAMESH KUMAR, Kuniaki Yoshitomi, Akira Ishikawa, Shugo Fukagawa, Noriyuki Kodama, Akihiro Tahira, Multi-Band Miniaturized Slot Antenna with Two-Stage Bandpass Filter, 2013 IEEE International Symposium on Antennas and Propagation and USNC-URSI National Radio ScienceMeeting, 2013.07, This paper presents the design and implementation of miniaturized slot antenna with two-stage impedance matching circuit for 800MHz and 2GHz up/down link multiband application. Our proposed multi-band antenna is designed and simulated by using commercial three-dimensional electromagnetic (EM) field simulator. Also, we fabricated this multi-band antenna on FR4 substrate and measured the frequency characteristics..
31. Yuharu Shinki, Daisuke Kanemoto, Keiji Yoshida, POKHAREL RAMESH KUMAR, Kuniaki Yoshitomi, Haruichi Kanaya, Wireless Power Transmission Circuit on a Small Planar Wide-Band Antenna, International technical conference of IEEE Region 10 (TENCON) 2013, 2013.10, This paper presents the design of wireless power transmission circuit on a small planar wide-band antenna. The proposed rectifying circuit consists of a microstrip line, a Schottky detector diode and a capacitor. Our proposed rectifying circuit can work at 2.45 GHz, 3.8 GHz and 5.8 GHz, namely, multiband operation, and circuit size is 56 mm x 43 mm x 1.6 mm. The proposed small planar wide-band antenna has a maximum gain of 1.26 dBi at 2.5 GHz, 0.37 dBi at 3.8 GHz and 3.32 dBi at 5.8 GHz. The maximum conversion efficiencies of this circuit achieved at free space are 26.8%, 29% and 43.3% at 2.5, 3.5 and 5.8 GHz with load resistances of 2000 Ω, 510 Ω, 1300 Ω and 0 dBm input power level..
32. Shoichiro Tsukamoto, Naoto Iizasa, Kuniaki Yoshitomi, POKHAREL RAMESH KUMAR, Keiji Yoshida, Reiji Hattori, Haruichi Kanaya, Daisuke Kanemoto, Development of a Rectenna for Batteryless Electronic Paper, International technical conference of IEEE Region 10 (TENCON) 2013, 2013.10, This paper describes the design of a rectenna for batteryless electronic paper. The rectenna is composed of a onesided directional flexible antenna and a booster rectifying circuit that is composed of a series resonant circuit and a Cockcroftwalton circuit. The proposed one-sided directional flexible antenna has a bottom floating metal layer that enables one-sided radiation. The booster rectifying circuit has an output of 3.5V DC for an input of 200mV and a 50ohm power source at 920MHz..
33. Emad Tammam, Yoshitomi Kuniaki, Ahmed Allam, Mohammed El-Sayed, Kanaya Haruichi, Yoshida Keiji, A Highly Miniaturized Planar Antenna With Dual Band-Notched Using Two Slot Types for UWB Wireless Communications
, 2012 Asia-Pacific Microwave Conference (APMC2012), 2012.12.
34. Emad Tammam, Yoshitomi Kuniaki, Ahmed Allam, Mohammed El-Sayed, Kanaya Haruichi, Yoshida Keiji, Miniaturization of a UWB Antenna With Dual Band-Notched at WLAN/WiMAX Frequency Bands, 2012 IEEE International Conference on Electronics Design, Systems and Applications (ICEDSA 2012), 2012.11.
35. Emad Tammam, Lingsheng Yang, Ahmed Allam, Mohammed Ragab, Yoshitomi Kuniaki, Pokharel Kumar Ramesh, Yoshida Keiji, Design of a Small Size UWB Antenna with Band-rejection Characteristics, JEC-ECC 2012 : 2012 Japan-Egypt Conference on Electronics, Communications and Computers , 2012.03.
36. Investigation of Low Impedance Line Structure Component Using a Circuit Model.