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Article type: Cover
Pages
Cover1-
Published: March 01, 2003
Released on J-STAGE: September 20, 2017
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Article type: Index
Pages
Toc1-
Published: March 01, 2003
Released on J-STAGE: September 20, 2017
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Mohammad ABDUL JALIL, Tetsuya MIZUMOTO, Hiroshi ISHIKAWA, Hisato UETSU ...
Article type: Article
Session ID: ROFT2003-40
Published: March 01, 2003
Released on J-STAGE: September 20, 2017
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Switching characteristics of ultrafast all-optical loop-structured switch (TOAD) is simulated. Switching in TOAD is performed by differential phase shift between two counter propagating light stream. In this paper, device parameters dependency of the switching characteristics of TOAD is investigated and a set of optimal device parameters are presented considering the effect of finite nonlinear element (SOA) length.
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Testu Ito, Atsushi Ozawa, Osamu Mikami, Ichiro Fujieda
Article type: Article
Pages
5-8
Published: March 01, 2003
Released on J-STAGE: September 20, 2017
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Aiming at the application to optical interconnection or optical mounting, Diffraction characteristics of a liquid crystal grating based on in-plane switching were studied. The structure is simple, and is an active element with large flexibility. We examined trial manufacture of the sample, evaluation of some characteristics, and asymmetric diffraction characteristics depending on the propagation direction of light. This is due to the asymmetric distribution of liquid crystal directors and the fact that the director distribution varies in the range of the order of a wavelength.
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Yoshikazu Murata, Yusuke Oyama, Kentaro Miyazato, Noritoshi Watanabe, ...
Article type: Article
Pages
9-12
Published: March 01, 2003
Released on J-STAGE: September 20, 2017
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We have proposed an use of micro lens array and 45-dgree micro mirror for coupling between an optical wiring and an optical device. In this paper, we explain the concept of optical surface mount technology with micro lens array and study coupling efficiency between a VCSEL and an optical fiber both theoretically and experimentally.
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Nozomi OZAWAr, Aiichiro TSUZUKU, Yoshiya ARAKAKI, Hiroki OHTA
Article type: Article
Pages
13-16
Published: March 01, 2003
Released on J-STAGE: September 20, 2017
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In order to realize the single frequency network in the digital terrestrial television broadcasting, high frequency accuracy and stability are needed. The Rubidium oscillator fulfills required frequency accuracy. However, the Rubidium oscillator is expensive. Then, because of the frequency accuracy of the TV radio wave, it is examined to use the color subcarrier for frequency standard. In this paper, we mentioned the frequency stability of the color subcarrier, and computer simulations of the PLL using the color subcarrier are also described.
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Takayukil SHIKAWA, Kouji IKEGAMI, Ikuji FUJITANI, Hirochika ONOZAWA, T ...
Article type: Article
Pages
17-20
Published: March 01, 2003
Released on J-STAGE: September 20, 2017
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An impedance matching technique applying a ferrite core for Medium Wave radio transmission is proposed. By experimental evaluation, this technique can change an impedance of output of a transmitter to that of a transmit antenna with good characteristics of a withstand lightning, and of a VSWR inside a transmission bandwidth. These characteristics can satisfy a practical standard.
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Takeshi MIZUKAWA
Article type: Article
Pages
21-24
Published: March 01, 2003
Released on J-STAGE: September 20, 2017
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One of the factors which degrade the receiving margin of digital terrestrial broadcasting, is disturbances which exist in the same channel. They can be easily detected, if they are large enough to be visible from OFDM waveform when they are observed with a spectrum analyzer. However, as for the disturbances which are totally invisible, it is difficult to detect their existence, or get hold of their D / U ratio, unless OFDM radiation is cut out.. Then, we have devised a technique by which we can presume the frequency of the disturbances and their D / U ratio by utilizing FFT output signal from a digital-broadcasting receiver before equalization. Furthermore, we have implemented this technique and also have conducted its operational test.
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Satoshi Kimura, Hiroyuki Hamazumi, Kazuhiko Shibuya
Article type: Article
Pages
25-28
Published: March 01, 2003
Released on J-STAGE: September 20, 2017
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In order to achieve broadcast wave relays in digital terrestrial broadcasting, it is important to have technologies that can improve the characteristics of signals that have deteriorated on the propagation path. One of the critical issues is the problem of co-channel interference, which occurs when digital and analog waves from other stations interfere with the desired signal at the relay station's receiving antenna. In this paper, we examine an algorithm for an OFDM adaptive array that forms a null in the direction of an interfering waves, by adaptively combining for each OFDM signal subcarrier from multiple reception antennas installed in the relay station.
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Katsuyuki FUJI, Koichi ITO, Shigeru TAJIMA
Article type: Article
Pages
29-32
Published: March 01, 2003
Released on J-STAGE: September 20, 2017
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Studies of wearable computers have attracted public attention in these days. And one of the area of interest is the communication system adopted in those wearable computers. As an example, wearable devices which use the human body as a transmission channel, have been developed. However, little is known about the transmission mechanism of such devices in the physical layer. In this paper, we proposed calculation models of the transmitter and the receiver attached to the arm using the FDTD method. From this model, we estimated the difference in the received signal level due to the electrode structures of the transmitter and the receiver under various conditions. Moreover, in order to verify the validity of these calculation models, we compared the calculated received signal levels to the measured ones by using a biological tissue-equivalent phantom.
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Article type: Appendix
Pages
App1-
Published: March 01, 2003
Released on J-STAGE: September 20, 2017
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Article type: Appendix
Pages
App2-
Published: March 01, 2003
Released on J-STAGE: September 20, 2017
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