Japanese | English

Masataka OHIRA, Dr.


Affiliation

Career

Academic Background

Academic Societies

Prizes

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)

  1. "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.
  2. "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.
  3. "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.
  4. "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

  1. "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.
  2. "60-GHz-band switched-beam eightsector antenna with SP8T switch for 180° azimuth scan," A. Miura, M. Ohira, S. Kitazawa, and M. Ueba, IEICE Trans. Commun., vol.E93-B, no.3, pp.551-559, Mar. 2010.
  3. "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.
  4. "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.
  5. "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
  6. "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.
  7. 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.
  8. "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.

Waveguide Filters

  1. "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.
  2. "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.
  3. "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.
  4. "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.
  5. "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.
  6. 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 Filters

  1. "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.
  2. "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.
  3. "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.
  4. "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.
  5. 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)
  6. Authors' Reply,” M. Ohira and Z. Ma, IEEE Trans. Microwave Theory and Tech., vol.61, no.12, pp.4284-4285, Dec. 2013.
  7. 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.
  8. "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.
  9. "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.
  10. "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.

Other Passive Circuits

  1. "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.
  2. "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.
  3. "Accurate Schiffman-type section design approach for microstrip line Wilkinson power divider," X. Wang, M. Ohira, and Z. Ma, IEICE Electronics Express, July 2016.
  4. "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.
  5. "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.
  6. "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.

Frequency Selective Surfaces (FSS)

  1. "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.
  2. "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.
  3. "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.
  4. "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.
  5. "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.
  6. "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

  1. "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.
  2. "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.
  3. "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.
  4. "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.
  5. "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.
  6. "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.
  7. "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.
  8. "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.
  9. "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.

Waveguide Filters

  1. "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.
  2. "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.
  3. "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.
  4. "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.
  5. "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.
  6. "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.
  7. 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.

Planar Filters

  1. "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.
  2. "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.
  3. "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)
  4. "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.
  5. "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.
  6. "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.
  7. "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.
  8. "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.
  9. "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.
  10. "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.
  11. "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.
  12. "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.
  13. "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.
  14. "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)
  15. "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.
  16. "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.
  17. "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. (R. Tomita: Young Researcher Encouragement Award)
  18. "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.
  19. "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.
  20. "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.
  21. "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.
  22. "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.
  23. "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.
  24. "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), Kuala Lumpur, Malaysia, Nov. 2017.

Other Passive Circuits

  1. "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.
  2. "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), Kuala Lumpur, Malaysia, Nov. 2017.

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.

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.

FreewareDownload
Current Version 0.50 in Japanese(Updated on Oct. 13, 2017)
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)
    [1] M. Ohira, Synfornee Lite Ver. 0.50 [Software]. Available: http://sirius.reso.ees.saitama-u.ac.jp/ohiram.html

(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.

Poster and Flyers

Multiband frequency selective surfaces (FSSs)

Multiband FSSs designed by genetic algorithm

2.45GHz-band 5th-order microstrip filtering antenna (filtenna)

Fully canonical Cul-de-Sac coupling bandpass filter at 2GHz band

Fully canonical transversal resonator array bandpass filter at 2GHz band

Dual-mode resonator filter at 2GHz band

Three-mode resonator filter at 5GHz band

Four-mode resonator filter at 5GHz band

X-band compact waveguide filter


X-band compact waveguide filter designed by genetic algorithm


X-band compact waveguide filter


X-band compact cutoff waveguide filter


60GHz-band sector-switched antenna for wireless LAN

2.4GHz-band multiport parasitic array radiator (MuPAR) antenna

430MHz electrically small monopole antenna

X-band elliptic-beam horn antenna

To top of this page