Kyushu University Academic Staff Educational and Research Activities Database
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Kuniaki Yoshitomi Last modified date:2018.06.11



Graduate School
Undergraduate School


E-Mail
Phone
092-802-6911
Fax
092-802-6913
Academic Degree
Doctor of Engineering
Country of degree conferring institution (Overseas)
No
Field of Specialization
Electromagnetic Wave Theory
Total Priod of education and research career in the foreign country
00years00months
Research
Research Interests
  • Design and analysis of small sized antennas
    keyword : antenna
    2010.09.
  • water pollution monitering by measuring active voltage from medaka
    keyword : safety engineering, water pollution monitering
    2005.09.
  • Study of absorption of electromagnetic wave by thin electromagnetic wave absorber
    keyword : electromagnetic wave absorber, electromagnetic compatibility
    1995.04~2007.10Shielding effect of electromagnetic shielding plates with apertures, a simple model of a shielding case of an electric device, was studied both analytically and experimentally. In the analytical study, we obtained a Green's function which represents the fields radiated from a source on a lossy ground plane. A Green's function for the field in a waveguidewas also obtained. A surface impedance boundary condition was introduced to simplify the boundary conditions for the lossy surfaces of the shielding plates. By using these Green's functions, analytical results of the field scattered by a slotin a lossy screen were obatined. It was found that a thin magnetic coating reduces the transmission power through a slot for the frequency higher than the resonant frequency of the slot, while for the frequency lower than that the transmitted power through the slot increases. This frequency dependence of the transmission powerthrough a slot is important when we use a magnetic coating material to reduce electromagnetic wave leakage through a slot. In the experimental study, he scattered fields by a slotin a metal plate covered with an absorbing material were measured. The results were in good agreement with the theoretical one..
Academic Activities
Papers
1. Hany A. Atallah, Adel B. Abdel-Rahman, Yoshitomi Kuniaki, Ramesh Kumar Pokharel, Design of compact frequency agile filter-antenna using reconfigurable ring resonator bandpass filter for future cognitive radios, International Journal of Microwave and Wireless Technologies, DOI: 10.1017/S1759078717001556, 83, 22-31, 2018.01, In this paper, a new miniaturized frequency agile filter-antenna with a wide reconfigurable frequency band is proposed for interweave cognitive radios (CRs). A tunable bandpass filter (BPF) composed of a symmetrical ring resonator is cascaded to the feed line of an ultra-wideband planar antenna. The structure of the proposed ring resonator BPF is simple and compact so that the total size of the proposed filter-antenna is smaller than that of a conventional system made of a separate antenna and BPF. The reconfigurability of the proposed filter-antenna is achieved by changing the operating frequency of the BPF by loading the ring resonator with a single varactor diode at its center. The fabricated prototype has successfully achieved a wide operational bandwidth of 1.43 GHz which covers continuous narrow bands from 4.65 to 6.08 GHz. Moreover, the operating tunable narrow bands have stable radiation characteristics. Good agreement bet een measurement and simulation results is demonstrated..
2. Hany A. Atallah, Adel B. Abdel-Rahman, Yoshitomi Kuniaki, Ramesh Kumar Pokharel, CPW-Fed UWB antenna with sharp and high rejection multiple notched bands using stub loaded meander line resonator, International Journal of Electronics and Communications (AEU), 83, 22-31, 2018.01, This paper presents a CPW-fed UWB filter-antenna with sharp and high rejection multiple band notches for band-notched UWB communication applications. The band notch operation is achieved by employing a sharp bandstop filter (BSF) with multiple reject bands using only one element meander line resonator at the bottom layer through theoretical calculations and parametric studies. The adjustment of the notched bands is successfully accomplished by loading the meander line with open ended stubs to modify the harmonic frequencies to the desired bands. The structure of the proposed BSF is simple and compact so that the proposed filter-antenna is achieved with the same size of the reference UWB antenna without an extra area. Measurement results show that the proposed filter-antenna has two notches at the WiMAX systems operating in the 5.8 GHz (5.725?5.85 GHz) and at the international telecommunication union (ITU) operating in the 8.2 GHz (8.025?8.4 GHz). Also, it has sharp rejection characteristics at the edges of the federal communication commission (FCC) band for UWB communications. The experimental measurements are in good agreement with theoretical and simulation results for the BSF and the filterantenna. Moreover, the filter-antenna exhibits stable omnidirectional radiation patterns except at the notched bands..
3. Fairus Tahar, Adel Barakat, Redzuan Saad, Kuniaki Yoshitomi, Ramesh K. Pokharel, Dual-Band Defected Ground Structures Wireless Power Transfer System With Independent External and Inter-Resonator Coupling, IEEE Transactions on Circuits and Systems II: Express Briefs, DOI: 10.1109/TCSII.2017.2740401, 64, 12, 1372-1376, 2017.08, This brief proposes a design methodology based on the admittance (J-) inverters for a dual-band wireless power transfer (WPT) system that employs two cascaded circulars defected ground structure (DGS) resonators with different capacitive loading to guarantee distinct resonances. A single microstrip line excites the two DGSs, and when two DGS resonators are coupled back to back, it transforms to a dual band pass filter leading to WPT at both bands. Each of the DGS resonators has independent coupling. Thus, the realized J-Inverters are designed independently. Also, we employ a single stub for the matching. This stub appears with a different length according to the operating frequency; hence, an independent external coupling is achieved at both frequencies. A compact size of 30 mm × 15 mm is fabricated achieving a WPT efficiency of more than 71% at a power transfer distance of 16 mm for both bands (0.3 and 0.7 GHz)..
4. 岩井 郁也, Yoshitomi Kuniaki, Haruichi Kanaya, Miniaturized high-band UWB array antenna, Microwave and Optical Technology Letters, 10.1002/mop.30599, 59, 7, 1651-1655, 2017.05, High-band ultra-wide band (UWB) miniaturized array antenna with coplanar wave guide (CPW) feed line is presented. Antenna element is composed of monopole antenna with truncated ground plane. Both antenna layer and ground pattern are placed on the top of the substrate. It is suitable for the miniaturized wireless devices such as three dimensional integrations or stacking of the multi layer. To obtain the wide band and flat gain characteristic, rectangular notches are inserted on the antenna layer, and optimized the current flow and antenna impedance. For array antenna, by changing the length of the CPW feed line, the antenna gain is suitable in the wide band which is 7–10.4 GHz (23 dB bandwidth). The total antenna size of the two array antenna is 16 mm 3 11.5 mm 30.418 mm. Simulated gain is 3.8 dB..
5. Hany A. Atallah, Adel B. Abdel-Rahman, Yoshitomi Kuniaki, Ramesh Kumar Pokharel, Reconfigurable Band-Notched Slot Antenna Using Short Circuited Quarter Wavelength Microstrip Resonators, Progress In Electromagnetics Research C, 68, 119-127, 2016.10, In this paper, a CPW feed ultrawideband (UWB) slot antenna with a single reconfigurable notched band is proposed for overlay cognitive radio (CR) systems. The proposed antenna utilizes two symmetrical short circuited quarter wavelength resonators at the top layer and close to the ground to create a single notch. The switching reconfiguration is achieved by changing the length of resonators to prevent the interference to the primary users that are operating in the wireless local area network (WLAN) band at 5.725–5.825 GHz and the international telecommunication union (ITU) band at 8.05–8.4GHz. The center frequency of the notched band can be tuned by selecting the length of the resonators, which is achieved by employing two ideal switches. Moreover, the proposed antenna has been fabricated and tested. The experimental data confirmed that the proposed design can selectively have a band notch over the two existent desired bands..
6. Hany A. Atallah, Adel B. Abdel-Rahman, Yoshitomi Kuniaki, Ramesh Kumar Pokharel, Mutual Coupling Reduction in MIMO Patch Antenna Array Using Complementary Split Ring Resonators Defected Ground Structure, Applied Computational Electromagnetics Society Journal, 31, 7, 737-743, 2016.07, In this paper, complementary split ring resonators (CSRRs) defected ground structure (DGS) is introduced to suppress surface waves and to reduce the mutual coupling between E-plane coupled two elements of a microstrip patch MIMO antenna array. The CSRRs-DGS is easily etched on the ground plane between the array elements. The CSRRs-based DGS acts as a bandstop filter between the array elements and operates in the same desired frequency band of the array at 9.2 GHz. Significant reduction of the electromagnetic (EM) mutual coupling is achieved between array elements with a reduced edge-to-edge spacing of 7.5 mm (0.22 ?o). Experimental results show that more than 30 dB isolation between the array elements is obtained using an array of CSRR-based DGS. Moreover, the antenna array parameters are successfully optimized with a numerical experimentation technique using a 3D full-wave EM simulator. The design of the proposed array is fabricated and measured for verification purposes. The proposed design has been simulated and validated experimentally. Good agreement is found between the simulated and the measured data..
7. Chai Eu Guan, Yoshitomi Kuniaki, Haruichi Kanaya, Derivation of the Optimum Distance between Periodically Spaced Vias for Leakage Suppression at S-band, MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, 10.1002/mop.29776, 58, 5, 1257-1260, 2016.05, In this letter, the optimum center-to-center separation between vias in the conductor-backed coplanar waveguide (CBCPW) is presented for leakage suppression in the dielectric region. Leakage mechanism at high frequencies associated with surface wave or parallelplate mode were widely studied in the past. In this work, antenna arrays have been used to compare leakage in CPW and CBCPW feed network at S-band. By using identical antenna elements, CPW-fed slot dipole antenna array has been compared against CBCPW-fed slot dipole antenna array with a ground via fence. Instead of using shorting pins with minimum nonzero gap, optimum center-to-center separation distance between vias has been derived from the bandgap phenomenon. Approximately 20% of total loss across the frequency range of interest in CPW feed network obtained from the comparison of the CPW-fed antenna array against the CBCPW-fed antenna array can be attributed to unwanted leakage in the dielectric substrate..
8. Hany A. Atallah, Adel B. Abdel-Rahman, Yoshitomi Kuniaki, Ramesh Kumar Pokharel, Design of Dual Band-Notched CPW-Fed UWB Planar Monopole Antenna Using Microstrip Resonators, Progress In Electromagnetics Research Letters, 59, 51-56, 2016.03, In this letter, a new coplanar waveguide (CPW) fed ultra-wideband (UWB) planar monopole antenna with dual band-reject characteristics is proposed. Two resonators of different lengths are employed at the bottom layer to create two notches at the frequency.
9. Hany A. Atallah, Adel B. Abdel-Rahman, Yoshitomi Kuniaki, Ramesh Kumar Pokharel, Tunable Band-Notched CPW-Fed UWB Monopole Antenna Using Capacitively Loaded Microstrip Resonator for Cognitive Radio Applications, Progress In Electromagnetics Research C, 62, 109-117, 2016.02, In this paper, a new compact coplanar waveguide (CPW) ultrawideband (UWB) antenna with an electronically tunable notched band is proposed for an overlay onto cognitive radio (CR) systems. The proposed antenna utilized a rectangular microstrip resonator in.
10. Lingsheng Yang, Yongan Zhu, Yoshitomi Kuniaki, CPW-Fed Reconfigurable Clover-Shaped Antenna with Switchable Circular Polarization, IEICE Transaction on Communications, E99-B, 1, 177-185, 2016.01, In this paper, a CPW-fed reconfigurable clover-shaped antenna with switchable circular polarization is proposed. This antenna consists of a clover-shaped patch, four p-i-n diodes, and two pairs of quarter-circular-rings. By electrically controlling the fo.
11. Lingsheng Yang, Tao Li, Feng Wang, Yoshitomi Kuniaki, Compact Tri-Bans MIMO Antenna for LTE/GSM Mobile Handset Application, IEICE Transaction on Communications, E99-B, 1, 177-185, 2016.01, A tri-band Multiple-input-multiple-output (MIMO) antenna system for LTE 700, LTE2500 and GSM 1800/1900 mobile handset application is presented. The whole system consists of four identical 3-D IFAs (inverted F antenna) folded on FR4 cuboids. Without any sp.
12. Hideharu Yoshioka, Lingsheng Yang, Emad Tamman, Yoshitomi Kuniaki, A highly compact dual-band WLAN/UWB monopole antenna, IEICE Electronics Express, 9, 3, 160-164, 2012.02.
13. Lingsheng Yang, Kuniaki Yoshitomi, A compact circular corner monopole antenna for UWB application, Microwave and Optical Technology Letters, 5, 4, 147-150, 2012.01.
14. L. Lolit Kumar Singh, Bhaskar Gupta, Partha P. Sarkar, Kuniaki Yoshitomi, and Kiyotoshi Yasumoto, Cross Slot Multifrequency Patch Antennas, MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Vol.5, No.6, pp.390-395, 2010.03.
15. L. Lolit Kumar Singh, Bhaskar Gupta, Partha P Sarkar, Kiyotoshi Yasumoto and Kunikai Yoshitomi, L-Shaped Slot Broadband Single Layer Rectangular Patch Antennas, International Journal of Microwave and Technology, vol. 5, no. 6, 390-395, Vol.5, No.6, pp.390-395, 2010.11.
16. K. Yoshitomi, A study on the excitation and the input impedance of an antenna, Asian Journal of Physics, Vol. 19, No. 2, 2009, 2009.05.
17. L. Lolit Kumar Singh, B. Gupta, K. Yoshitomi, and K. Yasumoto, New single layer wideband rectangular patch antenna, Asian Journal of Physics, Vol. 19, No. 2, 2009, 2009.05.
18. Kosei Moriyama and Kuniaki Yoshitomi, Apartment Electrical Wiring: A Cause of Extremely Low Frequency Magnetic Field Exposure in Residential Areas, Bioelectromagnetics, 10.1002/bem.20099, 26, 3, 238-241, vol.26, pp.238-241, 2005.04.
19. Kosei Moriyama, Hiroyuki Sato, Kenji Tanaka, Yoshiyuki Nakashima, and Kuniaki Yoshitomi, Extremely Low Frequency Magnetic Fields Originating from Equipment Used for Assisted Reproduction, Umbilical Cord and Peripheral Blood Stem Cell Transplantation, Transfusion, and Hemodialysis, Bioelectromagnetics, 10.1002/bem.20071, 26, 1, 69-73, vol.26, pp.69-73, 2005.01.
20. Measurement of RF noise in a magnetic sheild with a developed monopole antenna -- Effect of RF noise on FLL operation of dc-SQUID sensors --

K. Tashiro, I. Sasada, K. Yoshitomia and K. Kazami

Transactions of the Magnetics Society of Japan.
21. Measurement and reduction of power frequency magnetic fields in a residential area

K. Yoshitomi

The Transactions of the Institute of Electronics, Information and Communication Engineers B.
22. H.Jia, K.Yoshitomi, and K.Yasumoto, Rigorous analysis of E-/H-plane junctions in rectangular waveguides using Fourier transform technique, Progress In Electromagnetics Research, PIER, Vol.PIER21, pp.273--292, 1998.01.
23. K.Yasumoto and K.Yoshitomi, Efficient calculation of lattice sums for free-space periodic Green's function, IEEEE Transactions on Antennas and Propagation, 10.1109/8.777130, 47, 6, 1050-1055, Vol.47, No.6, pp.1050 -- 1055, 1999.06.
24. K.Yoshitomi, Radiation from a slot in an impedance surface, IEEE Transactions on Antennas and Propagation, 10.1109/8.954925, 49, 10, 1370-1376, Vol.49, No.10, pp.1370-1376, 2001.10.
25. H.Jia, K.Yoshitomi, and K.Yasumoto, Rigorous analysis of rectangular waveguide junctions by Fourier transform technique, Progress In Electromagnetics Research, PIER, Vol.20, pp.263--282, 1998.01.
Works, Software and Database
1. .
Presentations
1. 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.
2. 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.
3. 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.
4. 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.
5. 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.
6. 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.
7. 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.
8. 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.
9. 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.
10. 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.
11. 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.
12. 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.
13. 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.
14. 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.
15. 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.
16. 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.
17. 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.
18. 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.
19. 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.
20. 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.
21. 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.
22. 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..
23. 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..
24. 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..
25. 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..
26. 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..
27. 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.
28. 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.
29. 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.
30. Investigation of Low Impedance Line Structure Component Using a Circuit Model.
31. Investigation of Low Impedance Line Structure Component Using a Circuit Model.
Membership in Academic Society
  • The Japanese Society of Clinical Ecology
  • The Institute of Electrical and Electronics Engineers
  • The Institute of Electronics, Information and Communication Enginers