Search

Your search keyword '"Kunio Sawaya"' showing total 193 results
Start Over Author "Kunio Sawaya"
193 results on '"Kunio Sawaya"'

5. Design of a Wide Planar Waveguide Antenna for UHF Near-Field RFID Reader With High Reading Rate

Author

Kunio Sawaya, Qiang Chen, Machiko Oouchida, Masatomo Tokieda, and Yusuke Ozawa

Subjects
Physics, Standing wave, Waveguide (electromagnetism), Planar, Ultra high frequency, Null (radio), Acoustics, Organic Chemistry, Near and far field, Antenna (radio), Biochemistry, Electrical impedance
Abstract

UHF near-field RFID reader antenna based on leaky waveguide is proposed and the performance is evaluated using numerical simulation and experiment. In order to suppress the standing wave along transverse direction, a pair of notches is placed on the transverse edge of the mesh layer of the planar waveguide. Diversity operation by switching impedance of the end terminal of the planar waveguide antenna is also introduced to suppress the standing wave effect along longitudinal direction. Numerical simulation and experiment show that the near-field null lines parallel to the longitudinal direction is almost removed by the presence of the notches and the distribution of the field strength becomes almost uniform because of the utilization of the switching diversity. It is demonstrated that the reading performance of the commercial RFID tags is greatly improved by using the proposed RFID reader antenna with the diversity operation of termination impedance.

Published
2021
Full Text
View/download PDF

40. Millimeter-Wave Imaging Sensor

Author

Jun Uemura, Hiroyasu Sato, Kota Yamada, Hirai Haruyuki, Masamune Takeda, Junichi Takahashi, Koji Mizuno, Matsuzaki Tomohiko, Tsuyoshi Hasegawa, Kunio Sawaya, and Hirotaka Niikura

Subjects
Engineering, Physics::Instrumentation and Detectors, business.industry, Astrophysics::Instrumentation and Methods for Astrophysics, Electrical engineering, Astrophysics::Cosmology and Extragalactic Astrophysics, Optics, Transmission (telecommunications), Extremely high frequency, Electromagnetic shielding, Millimeter, Astrophysics::Earth and Planetary Astrophysics, Antenna (radio), Image sensor, business, Astrophysics::Galaxy Astrophysics
Abstract

In this chapter, the general principle and several systems for millimeter-wave sensors were discussed, and the state of development was also described. Furthermore, a 94-GHz-band passive millimeter-wave imaging sensor developed by Fujitsu Laboratories was shown in detail. The authors developed an ultra low-noise-receiver MMIC, and integrated it with a compact receiver module. The authors also realized a high-density imaging array to obtain millimeter-wave images in a short time. The considerations and the design method can also be used for other applications such as a broadband radio communication systems and radar.

Published
2021

49. Principle of Self-Complementarity and Application to Broadband Antennas

Author

Yasuto Mushiake, Takayuki Ishizone, and Kunio Sawaya

Subjects
Computer Science::Computer Science and Game Theory, Self-complementary antenna, Wireless broadband, Computer science, Frequency band, Astrophysics::Instrumentation and Methods for Astrophysics, Electronic engineering, Input impedance, Broadband antennas, Complementarity (physics), Computer Science::Information Theory
Abstract

Theory of self-complementarity which was derived through an investigation of the input impedance of slot antennas with arbitrary shape is described. Examples of self-complementary antennas, modified self-complementary antennas, and their application are presented. It is pointed out that the self-complementarity is very important to obtain the wide frequency band.

Published
2017
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results