High Frequency Engineering Lab., Doshisha University

Masataka OHIRA

Profile
Research
Papers
In't. Conf.
Filter Softwares
Designs
Schedule

Affiliation

Professor (April 2024 - Present), Doshisha University

Career

Associate Professor, Graduate School of Science and Engineering, Saitama University (April 2014 - March 2024)
Assistant Professor, Graduate School of Science and Engineering, Saitama University (April 2010 - March 2014)
Visiting Researcher, Advanced Telecommunication Research Institute International (ATR) (July 2011 - March 2013)
Visiting Researcher, Advanced Telecommunication Research Institute International (ATR) Wave Engineering Lab. (June 2010 - March 2011)
Researcher, Advanced Telecommunication Research Institute International (ATR) Wave Engineering Lab. (April 2006 - March 2010)

Academic Background

B. Eng., Department of Engineering, Doshisha University (April 1997 - March 2001)
M. Eng., Graduate School of Engineering, Doshisha University (April 2001 - March 2003)
D. Eng., Graduate School of Engineering, Doshisha University (April 2003 - March 2006)

Academic Societies

Achievements

Prizes

APMC 2022 Prize (2022)
IEICE Best Paper Award (2018)
IEEE MTT-S Japan Young Engineer Award (2014)
Michiyuki Uenohara Memorial Award (2014)
IEEE AP-S Japan Chapter Young Engineer Award (2012)
CJMW2011 (China-Japan Microwave Conference) Microwave Prize (2011)
IEICE Technical Committee on Antennas and Propagation Activity Award (2010)
IEEE Kansai Section Student Research Encouragement Award (2006)
IEICE Young Researcher's Award (2005)
IEICE Technical Commttiee on Microwaves Best Presentation Award (2003)

Academic Activities

Vice Chair, IEEE MTT-S Japan Chapter (2023-2024)
Technical Program Committee Chair, APMC 2022 Steering Committee (2020-2023)
Secretary, Technical Committee on Microwaves (2020-2022)
Member, APMC National Committee (2019-2023)
General Affair Committee Chair, MWE 2020 Steering Committee (2020)
Publicity & Web Master Chairs, TJMW2019 Steering Committee (2019)
Publicity Committee Member, MWE 2019 Steering Committee (2019)
Associate Editor, IEICE ELEX (2018-2021)
Workshop Member, IEICE Technical Committee on Antennas and Propagation (2018-)
Secretary, IEEE MTT-S Japan Chapter (2018-2019)
Publicity Committee Member, MWE 2018 Steering Committee (2018)
TPC Subcommittee Chair, APMC 2018 Steering Committee (2018)
TPC/Publication Co-Chair, TJMW2017 Steering Committee (2017)
Publicity Committee Member, MWE 2017 Steering Committee (2017)
Associate Editor, IEICE Trans. on Electron. Special Issue (2016)
General Affair Committee Chair, APMC 2018 Steering Committee (2016-2019)
Member, Technical Committee on Microwaves (2016-2020)
Student Advisor, IEICE Tokyo Section (2016-2024)
Publicity Committee Member, MWE 2016 Steering Committee (2016)
Secretary, IEICE Trans. on Electron. Special Issue (2016)
TPC/Publication Co-Chair, TJMW2016 Steering Committee (2016)
TPC Member/Publicity Committee Member, MWE 2015 Steering Committee (2015)
Secretary, TJMW2015 Steering Committee (2015)
TPC Vice Chair, VJMW2015 Steering Commttiee (2015)
TPC Subcommittee Chair, RFIT2015 (2015年)
GOLD/Student Committee Chair, IEEE MTT-S Japan Chapter (2014-2015)
TPC Secretary, TJMW2014 Steering Committee (2014)
Associate Editor, IEICE Trans. on Electron. Special Issue (2014)
TPC Subcommittee Chair, APMC 2014 Steering Committee (2014)
Assistant Secretary, IEICE Technical Committee on Microwaves (2013-2015)
Student Encouragement Member, TJMW2013 Steering Committee (2013)
General Affair Committee Vice Chair, APMC 2014 Steering Committee (2013-2015)
TPC Member, MWE 2013 Steering Committee (2013)
TPC Member, TJMW2011 Steering Committee (2011)
TPC Member, MWE 2011 Steering Committee (2011)
Member, IEICE Technical Committee on Antennas and Propagation (2009-2010)
Young Professionals Committee Chair, IEEE MTT-S Kansai Chapter (2008-2009)

Research Areas

Antenna theory, design, and measurements; filter theory, design and measurements; and other passive component designs.
- Research and development of microwave and millimeter-wave filters
- Research and development of comact antennas, smart antennas, and millimeter-wave antennas
- Electromagnetic analysis

Keywords

Electromagnetic waves
Filters, antennas & propagation
High frequency, microwave, millimeter-wave
Electromagnetic analysis and design
Electromagnetic circuit elements

Recent Research

(1) Fully Canonical Microwave Filter Designs

Transversal coupling filters
Cul-de-Sac coupling filters
Multimode filters

(2) Tunable/Reconfigurable Filter Designs

Transfer function reconfigurable filters
BPF/BSF switching filters
Tunable filters

(3) Filtering Antenna Designs

Microstrip filtering antenna designs
Tunable filtering antenna designs
Wideband filtering antenna designs

(4) Development of Automatic Passive Circuit Pattern Design Software

Automatic pattern generation using neural network and optimization techniques
Development of coupling matrix extraction techniques
Development of filter tuning techniques

Research Career

ATR Wave Engineering Laboratories (Apr. 2006 - Mar. 2010)

Research and development of 60-GHz-band switched beam antenna for multi-gigabit high-speed wireless loca area network (LAN)
Research and development of microwave smart antennas for an efficient spectrum use with space division multiplexing (SDM) technology in 2.4-GHz and 5-GHz wireless local area network
Investigation on microwave radio propagation in ICT equipment for next-generation machine-tomachine (M2M) wireless communications
Research and development of submillimeter-wave antennas for imaging technologies
Research and development of antenna miniaturization for U-VHF bands

Doshisha University (Apr. 2001 - Mar. 2006)

Analysis and design of multiband frequency-selective surfaces
Analysis and design of FSS-loaded waveguide filters
Analysis and design of planar filters
Analysis and design of horn antennas
Electromagnetic analysis such as the method of moments and mode-matching methods

Frequency Selective Surfaces (FSS)

"Multiband singl-layer frequency selective surface designed by optimization technique," M. Ohira, H. Deguchi, M. Tsuji, and H. Shigesawa, IEEJ Trans. on Fundamentals and Materials (Japanese Ed.), vol.123, no.3, pp.253-258, Mar. 2003.
"Multiband single-layer frequency selective surface designed by combination of genetic algorithm and geometry-refinement technique," M. Ohira, H. Deguchi, M. Tsuji, and H. Shigesawa, IEEE Trans. Antennas Propagat., vol.52, no.11, pp.2925-2931, Nov. 2004.
"Analysis of frequency selective surface with arbitrarily-shaped element by equivalent circuit model," M. Ohira, H. Deguchi, M. Tsuji, and H. Shigesawa, IEICE Trans. Electron. (Japanese Ed.), vol.J87-C, No.12, pp.1030-1037, Dec. 2004.
"Novel dual-resonant and dual-polarized frequency selective surface using eight-legged element and its experimental verification," M. Ohira, H. Deguchi, M. Tsuji, and H. Shigesawa, IEICE Trans. Electron., vol.E88-C, no.12, pp.2229-2235, Dec. 2005.

Antennas and Propagation

"Multiple-step rectangular horn with two orthogonal sectoral tapers for elliptical beam," H. Urata, M. Ohira, H. Deguchi, and M. Tsuji, IEICE Trans. Electron., vol.E90-C, no.2, pp.217-223, Jan. 2007.
"60-GHz-band switched-beam eightsector antenna with SP8T switch for 180Â° azimuth scan," A. Miura, M. Ohira, S. Kitazawa, and M. Ueba, IEICE Trans. Commun., vol.E93-B, no.3, pp.551-559, Mar. 2010.
"60-GHz wideband substrate-integrated-waveguide slot array using closely spaced elements for planar multisector antenna," M. Ohira, A. Miura, and M. Ueba, IEEE Trans. Antennas Propagat., vol.58, no.3, pp.993-998, Mar. 2010.
"Evolutionary generation of subwavelength planar element loaded monopole antenna," M. Ohira, H. Ban, and M. Ueba, IEEE Antennas and Wireless Propagat. Lett., vol.10, pp.1559-1562, Nov. 2011.
"Experimental characterization of microwave radio propagation in ICT equipment for wireless harness communications," M. Ohira, T. Umaba, S. Kitazawa, H. Ban and M. Ueba, IEEE Trans. Antennas Propagat., vol.59, no.12, pp.4757-4765, Dec. 2011
"Efficient gain optimization techniques for azimuth beam/null steering of inverted-F multiport parasitic array radiator (MuPAR) antenna," M. Ohira, A. Miura, M. Taromaru, and M. Ueba, IEEE Trans. Antennas Propagat., vol.60, no.3, pp.1352-1361, Mar. 2012.
“A new design formula of coupling coefficient between antenna and resonator for efficient design of filtering antenna,” M. Ohira, K. Yamanaka, and Z. Ma, IEICE Trans. Electron., vol.E99-C, no.7, pp.744-750, Jul. 2016.
"Intra-spacecraft wireless link and its application to spacecraft environmental tests," T. Toda, N. Kukutsu, S. Kitazawa, S. Ano, H. Kamoda, T. Kumagai, K. Kobayashi, M. Ohira, and S. Shimizu, Transactions of the Japan Society for Aeronautical and Space Sciences, Aerospace Technology Japan, vol.14, no.ists30, pp.21-26, Feb. 2017.
"[Invited] A tunable filtering antenna with frequency selectivity/tunability of constant absolute bandwidth and radiation characteristic," M. Ohira, T. Soma, and Z. Ma, IEICE Trans. Electron. (Japanese Ed.), vol.J103-C, no.9, pp.368-379, Sept. 2020.
"A 28 GHz band compact LTCC filtering antenna with extracted-pole unit for dual polarization," K. Sudo, R. Mikase, Y. Taguchi, K. Takizawa, Y. Sato, K, Sato, H. Hayafuji, and M. Ohira, IEICE Trans. Electron., vol.E106-C, no.11, pp.635-642, Nov. 2023.
"Design and experimental verification of parasitic-element loaded wideband filtering antennas over 30% frequency bandwidth," K. Sakiyama, M. Ohira, and Z. Ma, IEICE Trans. Electron. (Japanese Ed.), vol.J107-C, no.3, pp.77-86, Mar. 2024.

Filters

"Novel waveguide filters with multiple attenuation poles using dual-behavior resonance of frequency selective surfaces," M. Ohira, H. Deguchi, M. Tsuji, and H. Shigesawa, IEEE Trans. Microwave Theory Tech., vol.53, no.11, pp.3320-3326, Nov. 2005.
"A novel waveguide bandpass filter with multiple attenuation poles using four-armed square-loop FSSs," M. Ohira, H. Deguchi, M. Tsuji, and H. Shigesawa, IEICE Trans. Electron. (Japanese Ed.), vol.J89-C, no.7, pp.458-465, July 2006.
"Circuit synthesis for compact waveguide filters with closely-spaced frequency selective surfaces," M. Ohira, H. Deguchi, and M. Tsuji, International Journal of Microwave and Optical Technology, vol.1, no.2, pp.366-370, Aug. 2006.
"A new frequency selective window for constructing waveguide bandpass filters with multiple attenuation poles," M. Tsuji, H. Deguchi, and M. Ohira, Progress In Electromagnetics Research C, vol.20, pp.139-153, 2011.
"A novel feeding structure to generate multiple transmission zeros for miniature waveguide bandpass filters composed of frequency-selective surfaces," M. Ohira, Z. Ma, H. Deguchi, and M. Tsuji, IEICE Trans. Electron., vol.E94-C, no.10, pp.1586-1593, Oct. 2011.
“Improvement on stopband property of compact waveguide filters using hybrid resonances and antiresonances of cutoff waveguides and planar resonators,” T. Matsumoto, M. Ohira, and Z. Ma, IEICE Trans. on Electron. (Japanese Ed.), pp.524-532, vol.J96-C, no.12, Dec. 2013. (in Japanese)
"Planar-circuit bandpass filters consisting of arbitrarily-shaped elements," M. Ohira, H. Deguchi, M. Tsuji, and H. Shigesawa, IEICE Trans. Electron. (Japanese Ed.), vol.J89-C, no.5, pp.274-281, May 2006.
"Multi-resonator generation by genetic optimization for application to planar-circuit bandpass filters," M. Tsuji, H. Deguchi, A. Kido, and M. Ohira, IEEJ Trans. on Fundamentals and Materials, vol.129, no.10, pp.681-686, Oct. 2009.
"Resonant-mode characteristics of a new three-mode hybrid microstrip/slotline resonator and novel realization of compact bandpass filter with four transmission zeros," M. Ohira and Z. Ma, IEICE Trans. Electron., vol.E95-C, no.7, pp.1203-1210, Jul. 2012.
"A parameter-extraction method for microwave transversal resonator array bandpass filters with direct source/load coupling," M. Ohira and Z. Ma, IEEE Trans. Microwave Theory and Tech., vol.61, no.5, pp.1801-1811, May 2013.
“A design method of multi-mode filters with transmission zeros using synthesis theory and parameter extraction technique for transversal array network,” H. Aoyama, M. Ohira, and Z. Ma, IEICE Trans. on Electron. (Japanese Ed.), pp.471-479, vol.J96-C, no.12, Dec. 2013. (in Japanese)
“Authors' Reply,” M. Ohira and Z. Ma, IEEE Trans. Microwave Theory and Tech., vol.61, no.12, pp.4284-4285, Dec. 2013.
“A compact three-mode H-shaped resonator bandpass filter having high passband selectivity with four transmission zeros and wide stopband characteristic,” M. Ohira and Z. Ma, IEICE Trans. Electron., vol.E97-C, no.10, pp.957-964, Oct. 2014.
"A fully canonical bandpass filter design using microstrip transversal resonator array configuration," M. Ohira, T. Kato, and Z. Ma, IEICE Trans. Electron., vol.E99-C, no.10, pp.1122-1129, Oct. 2016.
"Design of compact ultra wide-band bandpass filters using short-circuited stubs with improved stopband characteristics," R. Hamano, Z. Ma, and M. Ohira, IEICE Trans. Electron. (Japanese Ed.), vol.J99-C, no.12, pp.618-624, Dec 2016.
"An improved coupling-matrix extraction method of microwave bandpass filters with de-embedding technique for transmission loss of input/output lines," R. Tomita, M. Ohira, Z. Ma, and X. Wang, IEICE Trans. on Electron. (Japanese Ed.), vol.J100-C, no.12, pp.569-579, Dec. 2017.
"A miniaturized dual-band bandpass filter using composite resonators with flexible frequency ratio," P. Wen, Z. Ma, H. Liu, S. Zhu, B. Ren, X. Wang, and M. Ohira, IEICE Electronics Express, vol.15, no.5, pp.1-6, Feb. 2018.
"Compact dual-band differential bandpass filter using quadruple-mode stepped-impedance square ring loaded resonators," B. Ren, H. Liu, Z. Ma, M. Ohira, P. Wen, X. Wang, X. Guan, IEEE Access, vol.6, pp.21850-21858, Apr. 2018.
"[Invited Paper] A tuning-less design method of microwave bandpass filters using neural network based inverse model," A. Yamashita, Z. Ma, and M. Ohira, IEICE Trans. Electron. (Japanese Ed.), vol.J101-C, no.8, pp.327-335, Aug. 2018.
"Balanced tri-band bandpass filter using sext-mode stepped-impedance square ring loaded resonators," B. Ren, Z. Ma, H. Liu, X. Guan, P. Wen, C. Wang, and M. Ohira, IEICE Electronics Express, vol.15, no.18, p.2018670, Aug. 2018.
"Coupling-matrix-based systematic design of single-DC-bias-controlled microstrip higher order tunable bandpass filters with constant absolute bandwidth and transmission zeros," M. Ohira, S. Hashimoto, Z. Ma, and X. Wang, IEEE Trans. on Microwave Theory and Tech., vol.67, no.1, pp.118-128, Jan. 2019.
"Miniature dual-band bandpass filter using modified quarter-wavelength SIRs with controllable passbands," B. Ren, Z. Ma, H. Liu, X. Guan, P. Wen, X. Wang, and M. Ohira, Electron. Lett., vol.55, no.1, pp.38-40, Jan. 2019.
"Compact dual-band bandpass filter and diplexer using hybrid resonant structure with independently controllable dual passbands," B. Ren, H. Liu, Z. Ma, M. Ohira, X. Guan, P. Wen, and X. Wang, Int. Journal of RF and Microwave Computer-Aided Eng., vol.29, no.1, e21435, Jan. 2019.
"Differential dual-band superconducting bandpass filter using multimode square ring loaded resonators with controllable bandwidths," B. Ren, Z. Ma, H. Liu, X. Guan, X. Wang, P. Wen, and M. Ohira, IEEE Trans. on Microwave Theory and Tech., vol.67, no.2, pp.726-737, Feb. 2019.
"Individually controllable dual-band bandpass filter with multiple transmission zeros and wide stopband," P. Wen, Z. Ma, H. Liu, S. Zhu, B. Ren, X. Guan, and M. Ohira, IEICE Electronics Express, vol.16, no.7, pp.1-5, Mar. 2019.
"Design and experiment of quasi millimeter-wave band box-type coupling SIW bandpass filter with transmission zeros using TE102 mode," Y. Shimizu, M. Ohira, and Z. Ma, IEICE Trans. Electron. (Japanese Ed.), vol.J103-C, no.1, pp.24-33, Jan. 2020.
"A novel deep-Q-network based fine-tuning approach for planar bandpass filter design," M. Ohira, K. Takano, and Z. Ma, IEEE Microwave and Wireless Comp. Lett., vol.31, no.6, pp.638-641, Mar. 2021.
"Highly selective and controllable superconducting dual-band differential filter with attractive common-mode rejection," B. Ren, X. Guan, H. Liu, Z. Ma, and M. Ohira, IEEE Trans. on Circuits and Systems II: Express Briefs, vol.69, no.3, pp.939-943, Mar. 2022.
"[Invited] Surrogate-based EM optimization using neural networks for microwave filter design," M. Ohira and Z. Ma, IEICE Trans. Electron., vol.E105-C, no.10, pp.466-473, Oct. 2022.
"Design of a compact triple-mode dielectric resonator filter with wide spurious-free performance," F. Liu, Z. Ma, W. Zhang, M. Ohira, D. Qiao, G. Pu, and M. Ichikawa, IEICE Trans. Electron., vol.E105-C, no.11, pp.660-666, Nov. 2022.
"A compact microstrip transversal coupling reconfigurable bandpass filter with highly variable center frequency, bandwidth, and transmission zeros," M. Ohira, S. Hashimoto, and Z. Ma, IEICE Trans. Electron. (Japanese Ed.), vol.J106-C, no.1, pp.46-54, Aug. 2022.
"Novel combined coaxial and dual-mode dielectric resonator BPFs with symmetric and asymmetric responses using virtual negative couplings," F. Liu, Z. Ma, M. Ohira, D. Qiao, G. Pu, and M. Ichikawa, IEEE Trans. on Microwave Theory Tech., vol.71, no.11, pp.4947-4956, Nov. 2023.
"Precise design of an 11-pole TM010 mode dielectric resonator BPF with novel capacitive coupling structures," F. Liu, Z. Ma, M. Ohira, D. Qiao, G. Pu, M. Ichikawa, IEICE Trans. Electorn. vol.E107-C, no.11, pp.472-478 (2024-11)

Other Passive Circuits

"Study on equivalent circuit of coaxial line to post-wall waveguide transition in 60-GHz band," W. Luo, M. Ohira, A. Miura, and M. Ueba, Microw. Opt. Tech. Lett., vol.52, no.3, pp.623-626, Jan. 2010.
"Coupled microstrip line Wilkinson power divider with open-stubs for compensation," X. Wang, M. Ohira, and Z. Ma, Electron. Lett., vol.52, no.15, pp.1314-1316, July 2016.
"Accurate Schiffman-type section design approach for microstrip line Wilkinson power divider," X. Wang, M. Ohira, and Z. Ma, IEICE Electronics Express, July 2016.
"Capacitive/Inductive compensation factor in coupled lines Wilkinson power divider design," X. Wang, M. Ohira, Z. Ma, I. Sakagami, A. Mase and M. Yoshikawa, Microw. Opt. Tech. Lett., vol.58, no.12, pp.2940-2944, Dec. 2016.
"A flexible two-section transmission-line transformer design approach for complex source and real load impedances," X. Wang, M. Ohira, and Z. Ma, IEICE Electronics Express, vol.14, no.1, pp.20161095, Jan. 2017.
"Dual-band design theory for dual transmission line transformer," X. Wang, Z. Ma, and M. Ohira, IEEE Microwave and Wireless Comp. Lett., vol.27, no.9, pp.782-784, Sept. 2017.
"Theory and experiment of two-section two-resistor Wilkinson power divider with two arbitrary frequency bands," X. Wang, Z. Ma, and M. Ohira, IEEE Trans. on Microwave Theory and Tech., vo.66, no.3, pp.1291-1300, Mar. 2018.
"Authors' reply," IEEE Microwave and Wireless Comp. Lett., X. Wang, T. Xie, G. Lu, Z. Ma, and M. Ohira, vol.28, no.12, pp.1158-1159, Dec. 2018.
"Tunable transmission-line transformer with two varactors and its application for Wilkinson power divider," X. Wang, N. Shinoda, Z. Ma, and M. Ohira, Int. Journal of Electron. and Comm., vol.98, pp. 259-264, Jan. 2019.
"Dual-band filtering power divider using dual-resonance resonators with ultrawide stopband and good isolation," P. Wen, Z. Ma, S. Zhu, B. Ren, Y. Song, X. Wang, and M. Ohira, IEEE Microwave and Wireless Comp. Lett., vol.29, no.2, pp.101-103, Feb. 2019.
"Synthesis theory of ultra-wideband bandpass transformer and its Wilkinson power divider application with perfect in-band reflection/isolation," X. Wang, Z. Ma, T. Xie, M. Ohira, C.-P, Chen, and G. Lu, IEEE Trans. on Microwave Theory and Tech., vol. 67, no. 8, pp. 3377-3390, Aug. 2019.
"A novel compact wideband microstrip Wilkinson power divider," W. Zhang, Z. Ma, F. Liu, and M. Ohira, IEICE Electronics Express, vol.18, no.19, pp.1-6, Oct. 2021.
"A parametric shape optimization using the Nyström-boundary integral equation method for complex eigenvalues of electromagnetic scattering problems in 2D," R. Misawa, Y. Takahashi, Z. Ma, and M. Ohira, Trans. of the Japan Society for Comp. Methods in Eng., no.21, pp.71-79, Dec. 2021.
"A novel 10 MHz-4 GHz Wilkinson power divider using lumped compensation elements," Z. Ma, W. Zhang, F. Liu, and M. Ohira, IEICE Electronics Express, Jan. 2022. (early access)
"Design of Wideband impedance transformers with different number and different mounting positions of the shunt stubs," W. Zhang, Z. Ma, F. Liu, M. Ohira, and X. Wang, IEICE Electronics Express, Jan. 2022. (early access)

Frequency Selective Surfaces (FSS)

"Optimized single-layer frequency selective surface and its experimental verification," M. Ohira, H. Deguchi, M. Tsuji, and H. Shigesawa, in Proc. of 32nd European Microwave Conf. (EuMC 2002), pp.981-984, Milan, Italy, Sep. 2002.
"Multiband single-layer frequency selective surface optimized by genetic algorithm with geometry-refinement technique," M. Ohira, H. Deguchi, M. Tsuji, and H. Shigesawa, IEEE AP-S Int. Symp. Antennas Propagat. (APS 2003), Columbus, OH, June 2003.
"A singular characteristic of single-layer frequency selective surface with the element optimized by GA,"M. Ohira, H. Deguchi, M. Tsuji, and H. Shigesawa, IEEE Topical Conf. on Wireless Commun. Tech., no.s16p01, Honolulu, HI, Oct. 2003.
"Equivalent circuit for frequency selective surface with complicated element extracted from eigenvalue analysis," M. Ohira, H. Deguchi, M. Tsuji, and H. Shigesawa, Proc. of Asia-Pacific Microwave Conf. (APMC 2004), Delhi, India, Dec. 2004.
"Eight-legged resonant element for multiband FSS and its experimental verification," M. Ohira, H. Deguchi, M. Tsuji, and H. Shigesawa, 2005 Int. Symp. on Antennas and Propagat. (ISAP 2005), pp.861-864, Aug. 2005.
"A high-performance frequency selective surface consisting of closely-packed eight-legged resonant elements," M. Ohira, H. Deguchi, M. Tsuji, and H. Shigesawa, 2005 Korea Japan Microwave Workshop (KJMW 2005), pp.46-49, Busan, Korea, Oct. 2005.

Antennas and Propagation

"Varactor-loaded inverted-F multiport parasitic array radiator antenna," M. Ohira, A. Miura, M. Ueba, M. Taromaru, and T. Ohira, IEEE AP-S Int. Symp. Antennas Propagat. (APS 2007), pp.5211-5214, Honolulu, June 2007.
"60GHz wideband shaped-beam antenna using closely-spaced waveguide slots for wireless LAN," M. Ohira, A. Miura, and M. Ueba, 2008 Int. Symp. on Antennas and Propagat. (ISAP 2008), pp.714-717, Oct. 2008.
"A bandwidth-enhanced low-profile antenna for in-machine wireless harness communications and its clearance distance evaluation," M. Ohira, IEEE AP-S Int. Symp. Antennas Propagat. Dig. (APS 2013), pp.978-979, Orlando, FL, July 2013.
"Microwave propagation characterization in automotive engine compartment for wireless harness communications," M. Ohira, S. Ano, S. Kitazawa, H. Ban, N. Kukutsu, and K. Kobayashi, IEEE AP-S Int. Symp. Antennas Propagat. Dig. (APS 2014), pp.1179-1180, Memphis, TN, July 2014.
"Intra-spacecraft wireless link and its application to spacecraft environmental tests," T. Toda, N. Kukutsu, S. Kitazawa, S. Ano, H. Kamoda, T. Kumagai, K. Kobayashi, M. Ohira, S. Shimizu, 30th Int. Symp. on Space Tech. and Science (ISTS), Kobe, Japan, July 2015.
"On the design method of microstrip filtering antennas using only amplitude property of input reflection responses," M. Ohira and Z. Ma, 2015 Thailand-Japan MicroWave (TJMW2015), Bangkok, Thailand, Aug. 2015. (Not published technical report)
"An efficient design method of microstrip filtering antenna suitable for circuit synthesis theory of microwave bandpass filters," M. Ohira and Z. Ma, 2015 Int. Symp. on Antennas and Propagat. (ISAP2015), pp.846-849, Hobart, Australia, Nov. 2015.
"Design of multistage microstrip filtering antenna by using parameter extraction method," K. Sato, M. Ohira, and Z. Ma, Proc. of 2016 Thailand-Japan MicroWave (TJMW2016), Bangkok, Thailand, June 2016. (Not published technical report)
"Coupling-matrix based design of microstrip filtering antenna with cross coupling between antenna and resonator," M. Ohira, T. Miyazaki, Z. Ma, and X. Wang, Proc. of 2017 Thailand-Japan MicroWave (TJMW2017), Bangkok, Thailand, June 2017. (Not published technical report)
"Design of microstrip wideband filtering antenna using network synthesis theory of wideband chebyshev filter," M. Ohira, K. Sato, and Z. Ma, Proc. of 2018 Thailand-Japan MicroWave (TJMW2018), Bangkok, Thailand, June 2018. (Not publsihed technical report)
"A filter-technique aided design of 60-GHz band planar single-feed dual-polarized antenna," M. Ohira and Z. Ma, Proc. of 2020 Int. Symp. Antennas and Propagation (ISAP2020), pp.91-92, Online, Jan. 2021.
"A 28 GHz band dual-polarized LTCC filtering antenna with extracted-pole unit," K. Sudo, R. Mikase, Y. Taguchi, K. Takizawa, Y. Sato, K. Sato, H. Hayafuji, and M. Ohira, Proc. of 2022 Asia-Pacific Microwave Conf. (APMC 2022), pp.306-308, Yokohama, Japan, Nov.-Dec. 2022. (K. Sudo: APMC 2022 Prize)
"Design of parasitic-element loaded wideband filtering antenna with very flat gain in 30% frequency bandwidth," K. Sakiyama, M. Ohira, and Z. Ma, Proc. of 2022 Asia-Pacific Microwave Conf. (APMC 2022), pp.312-314, Yokohama, Japan, Nov.-Dec. 2022.
"A 60-GHz band SIW inline-type filtering antenna with flat in-band gain and two transmission zeros," M. Ohira, M. Hoshino, and Z. Ma, Proc. of 2022 Asia-Pacific Microwave Conf. (APMC 2022), pp.518-520, Yokohama, Japan, Nov.-Dec. 2022.
"Design of microstrip filtering antenna with transmission zeros using even/odd-symmetric electric field distributions," R. Kono, M. Ohira, and Z. Ma, Proc. of 2022 Asia-Pacific Microwave Conf. (APMC 2022), pp.521-523, Yokohama, Japan, Nov.-Dec. 2022.
"A parasitic-element loaded wideband filtering antenna with flat gain in 40% frequency bandwidth," K. Sakiyama, M. Ohira,and Z. Ma, Proc. of 2023 Thailand-Japan MicroWave (TJMW2023), Bangkok, Thailand, Dec. 2023.
"Multi-band 7.1/8.5/20/30-GHz horn antenna with spline-taper and coaxial-groove walls," H. Nanno, H. Nishida, H. Deguchi, and M. Ohira, 2024 IEEE Int. Symp. on Antennas and Propagation and ITNC-USNC-URSI Radio Science Meeting, Florence, Italy, July 2024.
"Arbitrarily-shaped dual-linear polarization reflectarray elements independently controlled for dual-band applications," Y. Makino, H. Tanaka, H. Deguchi, and M. Ohira, 2024 IEEE Int. Symp. on Antennas and Propagation and ITNC-USNC-URSI Radio Science Meeting, Florence, Italy, July 2024.

Waveguide Filters

"Novel waveguide filters with multiple attenuation poles using frequency selective surfaces," M. Ohira, H. Deguchi, M. Tsuji, and H. Shigesawa, 2005 IEEE MTT-S Int. Microwave Symp. (IMS 2005), Long Beach, CA, June 2005.
"Circuit synthesis for compact waveguide filters with closely-spaced frequency selective surfaces," M. Ohira, H. Deguchi, M. Tsuji, and H. Shigesawa, 10th Int. Symp. on Microwave and Optical Tech. (ISMOT 2005), pp.811-814, Fukuoka, Japan, Aug. 2005.
"A new dual-behavior FSS resonator for waveguide filter with multiple attenuation poles," M. Ohira, H. Deguchi, M. Tsuji, and H. Shigesawa, Proc. of 35th European Microwave Conf. (EuMC 2005), pp.189-192, Paris, France, Oct. 2005.
"A novel resonant window having dual-behavior resonance for pseudo-elliptic waveguide filter," M. Ohira, H. Deguchi, and M. Tsuji, in Proc. of 36th European Microwave Conf. (EuMC 2006), pp.1083-1086, Manchester, UK, Oct. 2006.
"A novel coaxial-excited FSS-loaded waveguide filter with multiple transmission zeros," M. Ohira, Z. Ma, H. Deguchi, and M. Tsuji, Proc. of Asia-Pacific Microwave Conf. (APMC 2010), pp.1720-1723, Yokohama, Japan, Dec. 2010.
"A new type of compact evanescent-mode waveguide bandpass filter using planar dual-bahavior resonators," M. Ohira, T. Matsumoto, Z. Ma, H. Deguchi, and M. Tsuji, Proc. of Asia-Pacific Microwave Conf. (IMS 2011), pp.1023-1026, Melbourne, Australia, Dec. 2011.
“A cutoff-waveguide bandpass filter using antiresonant elements for sharp passband skirt and wide stopband characteristics,” M. Ohira, T. Matsumoto, and Z. Ma, Proc. of Asia-Pacific Microwave Conf. (APMC 2013), pp.447-449, Seoul, Korea, Nov. 2013.
"A circularly polarized wideband filtering antenna having flat in-band gain and large out-of-band rejection," M. Ohira, K. Sakiyama, Z. Ma, and H. Deguchi, Proc. of Asia-Pacific Microwave Conf. (APMC 2024), Bali, Indonesia, Nov. 2024.

Planar Filters

"Multi-resonator generation in arbitrarily-shaped planar-circuit filters by genetic optimization," A. Kido, H. Deguchi, M. Tsuji, and M. Ohira, Proc. of 37th European Microwave Conf. (EuMC 2007), pp.1241-1244, Munich, Germany, Oct. 2007.
"Compact high-performance planar bandpass filters with arbitrarily-shaped conductor patches and slots," T. Kido, H. Deguchi, M. Tsuji, and M. Ohira, Proc. of 38th European Microwave Conf. (EuMC 2008), pp.1165-1168, Amsterdam, The Netherlands, Oct. 2008.
"Resonant-mode behavior of a new slotline-embedded three-mode microstrip-line resonator and its filter application," M. Ohira, Z. Ma, and M. Kato, Proc. of 2011 China-Japan Joint Microwave Conf. (CJMW 2011), pp.326-329, Hangzhou, China, Apr. 2011. (CJMW2011 (China-Japan Microwave Conference) Microwave Prize)
"Characteristics and design formulas of a microstrip stub-loaded multi-mode ring resonator," Z. Ma, M. Ohira, T. Hotaka, C.-P. Chen, T. Anada, and Y. Kobayashi, Proc. of 2011 China-Japan Joint Microwave Conf. (CJMW 2011), pp.354-357, Hangzhou, China, Apr. 2011.
"Eigen-mode analysis of a novel three-mode microstrip/slot-line resonator and the development of a compact bandpass filter with multiple transmission zeros and wide stopband property," M. Ohira and Z. Ma, 2011 IEEE MTT-S Int. Microwave Symp. (IMS 2011), pp.1-4, Baltimore, MD, June 2011.
"Design of a broadband bandpass filter using microstrip stubs-loaded three-mode resonator," Z. Ma, T. Kimura, M. Ohira, C.-P. Chen, and T. Anada, Proc. of Asia-Pacific Microwave Conf. (APMC 2011), pp.139-142, Melbourne, Australia, Dec. 2011.
"Novel multi-mode ring resonator transversal array bandpass filter with very high skirt selectivity using multiple transmission zeros," M. Ohira and Z. Ma, 2012 IEEE MTT-S Int. Microwave Symp. (IMS 2012), Montreal, Canada, June 2012.
"A novel compact high-performance microstrip 26GHz ultra-wideband (UWB) bandpass filter for vehicle radar systems," Z. Ma, M. Ohira, C.-P. Chen, and T. Anada, IEEE MTT-S Int. Microw. Workshop Series on Millimeter Wave Wireless Tech. and Applications (IMWS 2012), Nanjing, China, Sep. 2012.
"Compact bandpass filter with a sharp roll-off response using multi-path coupling scheme of H-shaped resonator," M. Ohira and Z. Ma, Proc. of Asia-Pacific Microwave Conf. (APMC 2012), pp.1130-1132, Kaohsiung, Taiwan, Dec. 2012.
"Circuital modeling and physical understanding of dissipation effects for coupled resonator filters transformed into transversal array configuration," M. Ohira and Z. Ma, Proc. of 2013 Int. Symp. on Electromagnetic Theory (EMTS 2013), pp.53-56, Hiroshima, Japan, May 2013.
"Deterministic extraction of direct source/load coupling and its application to multi-mode filter designs based on transversal array network theory," M. Ohira, H. Aoyama, and Z. Ma, 2013 IEEE MTT-S Int. Microwave Symp. (IMS 2013), Seattle, WA, June 2013.
"Physical interpretation of frequency-dependent S/L coupling in multi-mode bandpass filter and its design approach for generation of multiple finite transmission zeros," M. Ohira, H. Aoyama, and Z. Ma, 2014 IEEE MTT-S Int. Microwave Symp. (IMS 2014), Tampa, FL, June 2014.
"Design of a quasi-millimeter-wave UWB bandpass filter using microstrip dual-mode ring resonator and half-wavelength resonators," Z. Ma, Y. Wang, M. Ohira, C.-P. Chen, and T. Anada, The XXXI General Assembly of the International Union of Radio Science (URSI GASS 2014), Beijing, China, Aug. 2014.
"Microstrip lowpass filters with improved frequency responses using coupled-line hairpin resonators," J. Tsurumi, Z. Ma, and M. Ohira, Proc. of Asia-Pacific Microwave Conf. (APMC 2014), pp.1154-1156, Sendai, Japan, Nov. 2014. (J. Tsurumi: APMC 2014 Student Prize)
"A novel microstrip filter structure consisting of transversal resonator array and its fully canonical bandpass filter design," M. Ohira, T. Kato, and Z. Ma, 2015 IEEE MTT-S Int. Microwave Symp. (IMS 2015), Phoenix, AZ, May 2015.
"Novel microstrip realization and straightforward design of fully canonical Cul-de-Sac coupling bandpass filters," M. Ohira, T. Kato, and Z. Ma, 2016 IEEE MTT-S Int. Microwave Symp. (IMS2016), San Francisco, CA, May 2016.
"A simple and fast tuning technique for direct-coupled resonator filter design," R. Tomita, M. Ohira, and Z. Ma, Proc. of 2016 Thailand-Japan MicroWave (TJMW2016), Bangkok, Thailand, June 2016. (Not published technical report) (R. Tomita: Young Researcher Encouragement Award)
"Physical realization and systematic design of microwave bandpass filters with generalized Chebyshev function Response," M. Ohira and Z. Ma, Proc. of 2016 Thailand-Japan MicroWave (TJMW2016), Bangkok, Thailand, June 2016.
"A compact quasi-millimeter-wave microstrip wideband bandpass filter," Z. Ma, M. Ai, M. Ohira, C. Chen, and T. Anada, 2016 IEEE Int. Conf. on Ubiquitous Wireless Broadband, Najing, China, Oct. 2016.
"A novel eigenmode-based neural network for fully automated microstrip bandpass filter design," M. Ohira, A. Yamashita, Z. Ma, and X. Wang, 2017 IEEE MTT-S Int. Microwave Symp. (IMS2017), Honolulu, HI, June 2017.
"Design of microstrip bandpass filters using neural network based on eigenmodes," A. Yamashita, M. Ohira, Z. Ma, and X. Wang, Proc. of 2017 Thailand-Japan MicroWave (TJMW2017), Bangkok, Thailand, June 2017. (Not published technical report)
"A fourth-order tunable bandpass filter with constant absolute bandwidth and transmission zeros," S. Hashimoto, M. Ohira, Z. Ma, and X. Wang, Proc. of 2017 Thailand-Japan MicroWave (TJMW2017), Bangkok, Thailand, June 2017. (Not published technical report)
"Design of a compact diplexer using dual-mode microstrip and slotline resonators," B. Ren, Z. Ma, H. Liu, M. Ohira, P. Wen, X. Wang, and X. Guan, 2017 6th Asia-Pacific Conf. on Antennas and Propagat. (APCAP2017), Xi'an, China, Oct. 2017.
"Compact dual-band bandpass filter using stub-loaded stepped impedance resonators with mixed electric and magnetic couplings," P. Wen, Z. Ma, H. Liu, M. Ohira, B. Ren, and X. Wang, Proc. of 2017 Asia-Pacific Microwave Conf. (APMC2017), pp.803-805, Kuala Lumpur, Malaysia, Nov. 2017.
"Differential dual-band filter with flexible frequency ratio using H-shaped composite resonator for SCDMA and LTE applications," P. Wen, Z. Ma, M. Ohira, X. Wang, H. Liu, B. Ren, and X. Guan, Proc. of 2017 IEEE Electrical Design of Advanced Packaging and Systems (EDAPS 2017), Haining, Hangzhou, China, Dec. 2017.
"A new microstrip bandstop filter for fully canonical Cul-de-Sac coupling configuration," M. Ohira, M. Kanomata, Z. Ma, and X. Wang, Dig. of IEEE MTT-S Int. Microwave Symp. (IMS2018), pp.708-711, Philadelphia, PA, June 2018.
"A novel microstrip symmetric diagonal cross-coupling quadruplet bandpass filter using even/odd-mode stepped impedance resonators," R. Mikase, M. Ohira, Z. Ma, and X. Wang, Dig. of IEEE MTT-S Int. Microwave Symp. (IMS2018), pp.712-715, Philadelphia, PA, June 2018. (R. Mikase: IMS2018 Student Paper Competition Finalist)
"[Invited] Automated microstrip bandpass filter design using feedforward and inverse models of neural network," M. Ohira, A. Yamashita, Z. Ma, and X. Wang, Proc. of 2018 Asia-Pacific Microwave Conf. (APMC 2018), pp.1292-1294, Kyoto, Japan, Nov. 2018.
"Novel compact dual-band BPF using stub-loaded shorted stepped-impedance resonators," P. Wen, Z. Ma, H. Liu, S. Zhu, M. Ohira, C. Wang, X. Guan, and B. Ren, Proc. of 2018 Asia-Pacific Microwave Conf. (APMC 2018), Kyoto, pp.22-24, Japan, Nov. 2018.
"Design of balanced dual-band superconducting bandpass filter with high selectivity and deep common-mode suppression," B. Ren, Z. Ma, H. Liu, M. Ohira, X. Guan, and P. Wen, Proc. of 2018 Asia-Pacific Microwave Conf. (APMC 2018), pp.423-425, Kyoto, Japan, Nov. 2018.
"Compact multi-band differential bandpass filters using microstrip multi-moderesonators," B. Ren, Z. Ma, H. Liu, X. Guan, P. Wen, and M. Ohira, IEEE MTT-S Int. Wireless Symp., Guangzhou, China, May 2019.
"Design of compact wideband bandstop filters using microstrip ring structures," T. Tabei, Z. Ma, and M. Ohira, Proc. of 2019 Thailand-Japan MicroWave (TJMW2019), Nonthabuuri, Thailand, June 2019. (Not publsihed technical report)
"A fully reconfigurable microstrip transversal resonator array bandpass filter," M. Ohira, S. Hashimoto, and Z. Ma, Proc. of 2019 Thailand-Japan MicroWave (TJMW2019), Nonthabuuri, Thailand, June 2019. (Not publsihed technical report)
"A compact wideband bandstop filter using microstrip ring structure," T. Tabei, Z. Ma, and M. Ohira, Proc. of 23rd Int. Conf. on Applied Electromagnetics and Comm. (ICECOM 2019), Dubrovnik, Croatia, Oct. 2019.
"A new microstrip reconfigurable transversal coupling bandpass filter with highly controllable number and positions of transmission zeros," M. Ohira, S. Hashimoto, and Z. Ma, Proc. of Asia-Pacific Microwave Conf. (APMC2019), pp.1963-1965, Singapore, Dec. 2019.
"A forward model to output coupling matrix elements fromplanar filter images using CNN," R. Shibata, M. Ohira, and Z. Ma, Thailand-Japan MicroWave Student Workshop, Online, Dec. 2020. (Not publsihed)
"Design of an 11-pole BPF using cascaded triplets of TM010 mode dielectric ring resonators," F. Liu, Z. Ma, W. Zhang, M. Ohira, D. Qio, G. Pu, and M. Ichikawa, Proc. of IEEE MTT-S Int. Conf. on Numerical Electromagnetic and Multiphysics Modeling and Opt. (NEMO2020), Online, Dec. 2020.
"A microstrip box-type coupling bandpass filter using even/odd-symmetric electric field distributions of half-wavelength resonator," M. Ono, M. Ohira, Z. Ma, Proc. of Asia-Pacific Microwave Conf. (APMC2020), pp.415-417, Online, Dec. 2020.
"A novel deep-Q-network based fine-tuning approach for planar bandpass filter design," M. Ohira, K. Takano, and Z. Ma, presented at IEEE MTT-S Int. Microwave Symp., Online, June 2021.
"Design of wideband bandpass filter with equal-ripple attenuation in the passband," P. Wen, Z. Ma, S. Zhu, F. Liu, and M. Ohira, IEEE Int. Workshop on Electromagnetics: Applications and Student Innovation Competition (IEEE iWEM2021), Nov. 2021.
"A novel convolutional-autoencoder based surrogate model for fast S-parameter calculation of planar BPFs," R. Shibata, M. Ohira, and Z. Ma, IEEE MTT-S Int. Microwave Symp. (IMS), pp.498-500, Denver, CO, June 2022.
"[Invited] Neural-network assisted automatic design of microstrip cross-coupled bandpass filter," M. Ohira, A. Yamashita, and Z. Ma, 2022 URSI-Japan Radio Science Meeting (URSI-JRSM 2022), p.84, Tokyo, Japan, Sept. 2022.
"Synthesis design of wideband differential bandpass filter with intrinsic cm noise rejection using branch-line configuration," P. Wen, Z. Ma, S. Zhu, F. Liu, and M. Ohira, Proc. of 2022 Asia-Pacific Microwave Conf. (APMC 2022), pp.464-466, Yokohama, Japan, Nov.-Dec. 2022.
"Synthesis design of equal-ripple wideband balanced bandpass filter based on coupled-lines and branch-lines," Y. Jiang, P. Wen, Z. Ma, S. Zhu, C. Zhang, F. Liu, and M. Ohira, 2023 Int. Conf. on Microwave and Millimeter Wave Technology (ICMMT), pp.1-3, Qingdao, China, May 2023.
"A deep-reinforcement-learning assisted microstrip BPF design approach for multiple specifications," M. Ohira, Y. Asai, and Z. Ma, Proc. of 2023 Asia-Pacific Microwave Conf. (APMC 2023), Taipei, Taiwan, Dec. 2023.
"A novel box-like coupling microstrip diplexer with high skirt selectivity, high isolation, and wide stopband," M. Ohira, Y. Nishiyama, Z. Ma, and H. Deguchi, 2024 Thailand-Japan MicroWave (TJMW2024), Bangkok, Thailand, Oct. 2024.
"A new fourth-order box-coupling microstrip BSF with simultaneous excitation of multiple resonators," K. Hirota, M. Ohira,and Z. Ma, Proc. of 2023 Thailand-Japan MicroWave (TJMW2023), Bangkok, Thailand, Dec. 2023.
"Accurate design of higher-performance bandpass filters using multi-mode dielectric resonators for wireless communication base stations," F. Liu, Z. Ma, M. Ohira, D. Qiao, G. Pu, and M. Ichikawa, Proc. of Asia-Pacific Microwave Conf. (APMC 2024), Bali, Indonesia, Nov. 2024.

Others

"Bandwidth enhancement of coaxial line to postwall waveguide transition using short-ended straight post in 60-ghz band," W. Luo, M. Ohira, A. Miura, and M. Ueba, Proc. of Asia-Pacific Microwave Conf. (APMC 2008), pp.1-4, Hong Kong, China, Dec. 2008.
"Dual-band bandpass filter type Wilkinson power divider with microstrip composite resonators," X. Wang, N. Kimata, Z. Ma, and M Ohira, Proc. of 2017 Asia-Pacific Microwave Conf. (APMC2017), pp.299-301, Kuala Lumpur, Malaysia, Nov. 2017.
"Compact tunable Wilkinson power divider with simple structure," X. Wang, Z. Ma, M. Ohira, C.-P. Chen, and T. Anada, Proc. of 2018 Europ. Microwave Conf. (EuMC2018), pp.41-44, Madrid, Spain, Sept. 2018.
"Design theory of dual-band Wilkinson power divider with different frequency ratio ranges," A. Song, X. Wang, Z. Ma, and M. Ohira, Proc. of 2018 Asia-Pacific Microwave Conf. (APMC 2018), pp.1489-1491, Kyoto, Japan, Nov. 2018.
"Two types of dual-band bandpass filtering Wilkinson power divider with microstrip composite resonators," N. Zhang, X. Wang, N. Kimata, Z. Ma, and M. Ohira, 2019 Int. Conf. on Microwave and Millimeter Wave Technology (ICMMT), Guangzhou, China, May 2019.
"Balanced-to-unbalanced filtering power divider with stub-loaded dual-mode resonators," P. Wen, Z. Ma, S. Zhu, H. Liu, B. Ren, and M. Ohira, Proc. of Int. Symp. on Antennas and Propagat. (ISAP 2019), Xi'an, China, Oct. 2019.
"Multi-isolation resistors in coupled line section for Wilkinson power divider and its optimization," X. Wang, Z. Ma, M. Ohira, and C.-P. Chen, Proc. of Asia-Pacific Microwave Conf. (APMC2019), pp.350-352, Singapore, Dec. 2019.
"A novel design of wideband impedance transformers with applications to wideband BPFs," W. Zhang, Z. Ma, F. Liu, M. Ohira, and X. Wang, IEEE Int. Workshop on Electromagnetics: Applications and Student Innovation Competition (IEEE iWEM2021), Nov. 2021.
"High selectivity balanced-to-unbalanced filtering power divider with stub-loaded dual-mode resonators," P. Wen, Z. Ma, and M. Ohira, Proc. of Asia-Pacific Microwave Conf. (APMC2021), Dec. 2021.
"Development of robotic system without wired connections at joints by wireless communication and wireless power transfer," K. Serizawa, S. Shimizu, H. Sekiya, and M. Ohira, IEEE Int. Symp. on Personal, Indoor and Mobile Radio Comm., (IEEE PIMRC2022), Online, Sept. 2022.

Invited talks

M. Ohira, "[Invited Talk] Future Microwave Circuit Design Assisted by Neural Networks - Microwave Planar Filter Design as an Example-," Rump Session in 2019 Global Symposium on Millimeter Waves (GSMM 2019), Sendai, Japan, May 2019.

Workshop

M. Ohira, "A parameter-extraction method for transversal resonator array bandpass filters and its applications to multi-mode filter designs," Workshop WS1D in 2014 Asia-Pacific Microwave Conf. (APMC 2014), Sendai, Japan, Nov. 2014.
M. Ohira, "Basic and advanced filtenna designs," Short Course TU2-F6 in 2022 Asia-Pacific Microwave Conf. (APMC 2022), Yokohama, Japan, Nov.-Dec., 2022.

Tutorial talks

M. Ohira, "Genetic Algorithm Design for Applications to Microwave Filters and Antennas," TJMW2012 (Thailand-Japan MicroWave) Microwave Theory and Techniques Tutorial MW-3, pp.87-104, Chulalongkorn University, Bangkok, Thailand, Aug. 2012.
H. Kayano and M. Ohira, "Fundamentals of Microwave Filters: Synthesis Theory and Design Techniques," TJMW2013 (Thailand-Japan MicroWave) Short Courses: Tutorial 4, Kasetsart University, Bangkok, Thailand, Dec. 2013.
M. Ohira, "Microwave planar bandpass filter design for student design competition," Tutorial Session of 2016 Thailand-Japan MicroWave (TJMW2016), KMUTNB, Bangkok, Thailand, June 2016.

Synfornee: Synthesis for Filter Network Elements

(1) Synfornee Lite (Freeware in Japanese)

Basic Functions

Synthesize a coupling matrix of direct resonator coupled bandpass filters having Chebyshev and Butterworth functions
Calculate coupling coefficients and external Q factors in bandpass frequency domain from coupling matrix in lowpass prototype freqeuncy domain.
Calculate frequency responses of BPF from coupling matrix in lowpass prototype freqeuncy domain..
Calculate frequency responses of BPF by inputting arbitrary values in coupling matrix.

GUI

Visually show a coupling matrix in matrix form.
Visually show frequency responses of S-parameters in graphs.

Read and Save

Save S-parameters as CSV files.
Save and copy coupling matrix as CSV file.
Read coupling matrix from CSV file.

Freeware： Download
Current Version 0.60 in Japanese（Updated on Apr. 19, 2018）
Notes:
(1) This software is compatible with Windows 7, Windows 8, Windows 10.
(2) This software requires .NET Framework 4.5.2.
(3) I am not responsible for any damage caused by this software.
(4) Calculation accuracy is not guaranteed for all settings, because approximation is used for coupling matrix calculation.
(5) There may be bugs ... m(_ _)m
Request:
If you write papers using this software, it will encourage development if you cite my software in Reference as follows. (The format is not limited to the bottom)

Synfornee Lite

(2) Synfornee (Full version in Japanese)

Basic Functions

Synthesize a coupling matrix of transversal array filters (BPF and BSF) having a generalized Chebyshev function.
Synthesize a coupling matrix of direct resonator coupled bandpass filters having Chebyshev and Butterworth functions
Calculate coupling coefficients and external Q factors in bandpass frequency domain from coupling matrix in lowpass prototype freqeuncy domain.
Calculate frequency responses of BPF from coupling matrix in lowpass prototype freqeuncy domain..
Calculate frequency responses of BPF by inputting arbitrary values in coupling matrix.

Advanced Functions

Calculate frequency responses in lowpass prototype frequency domain as well.
Transform coupling topology from transversal coupling to other couplings such as folded canonical and fully-canonical Cul-de-Sac coupling.
Calculate frequency responses of lossy filter by inputting unloaded Q factor of each resonator.
Calculate frequency responses of S11 and S21 phases．
Calculate frequency responses of group delay．
Calcualte frequency responses of stored energy of each resonator for 1W-power input.

GUI

Visually show a coupling matrix in matrix form.
Visually show frequency responses of S-parameters in graphs.

Read and Save

Save S-parameters as CSV files.
Save and copy coupling matrix as CSV file.
Read coupling matrix from CSV file.

References

R. J. Cameron, R. Mansour, C. M. Kudsia, Microwave Filters for Communication Systems: Fundamentals, Design and Applications, July 2007.
M. Ohira, "Introduction to theory, analysis, and design of microwave filters in new era of wireless," Microwave Workshops & Exhibition (MWE 2015), WE4B (in Japanese), Nov. 2015.
M. Ohira and Z. Ma, "Theoretical relations between unloaded Q factor, stored energy, group delay, and insertion loss derived from coupling matrix of filter circuit," IEICE Tech. Report (in Japanese), vol.117, no.17, MW2017-17, pp.55-60, May 2017.