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Displaying 1-10 of 10 articles from this issue
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Article type: Cover
Pages Cover1-
Published: May 24, 2002
Released on J-STAGE: June 23, 2017
CONFERENCE PROCEEDINGS FREE ACCESSDownload PDF (13K) -
Article type: Index
Pages Toc1-
Published: May 24, 2002
Released on J-STAGE: June 23, 2017
CONFERENCE PROCEEDINGS FREE ACCESSDownload PDF (34K) -
Hisaaki Karakama, Koichi Sakaguchi, Nozomu HasebeArticle type: Article
Session ID: ROFT2002-53
Published: May 24, 2002
Released on J-STAGE: June 23, 2017
CONFERENCE PROCEEDINGS FREE ACCESSGenerally, an array antenna is designed by using the array factor. However, the conventional design method is not taking into account of mutual coupling between elements. So the resultant beam width and the side-lobe levels of the array deviate from the desired values. In this paper a new design method of array antenna with reflector is proposed. All elements' lengths are adjusted in order to suppress the reactance component of each element. Therefore all elements are worked as pure resistance, but they do not have same values. The desired current distribution of the array is obtained by adjusting the exciting voltage of each element because each element has no reactance component by adjusting the elements' lengths. It takes into account of mutual coupling between elements. The proposed array antenna design method is very simple.View full abstractDownload PDF (436K) -
Yoshio KOYANAGI, Koichi OGAWA, Koichi ITOArticle type: Article
Session ID: ROFT2002-54
Published: May 24, 2002
Released on J-STAGE: June 23, 2017
CONFERENCE PROCEEDINGS FREE ACCESSThe near field distributions of the portable phone antenna close to the phantom have been analyzed to elucidate a general mechanism of SAR distribution. In general the SAR distribution near the loss mediums is not related to the incident E field but to the incident H field. But we usually estimate the SAR by use of the internal E field data so it is not known that the fields evaluated on the inside and outside of a medium differ. For example, the peak E field data of the half wave dipole antenna is around the tip of the element but the peak SAR is exists on the surface of the phantom near the feed point. So the tendencies differ greatly inner the boundary plane from the outer side. In this report, the effect of the permittivity and the conductivity of the loss mediums for the near field distribution have been investigated by use of a half wave dipole antenna close to the COST 244 phantom at 2GHz. The results indicate that the SAR distributions are formed from two factors, one is the tanδ of the loss mediums, and another is difference value of the complex permittivity that attenuate the normal component of incidence E on the boundary.View full abstractDownload PDF (598K) -
Hiroshi FUJITA, Kazuo MATSUSHITAArticle type: Article
Session ID: ROFT2002-55
Published: May 24, 2002
Released on J-STAGE: June 23, 2017
CONFERENCE PROCEEDINGS FREE ACCESSThis paper describes study on an allowable feeder power at OFDM signal transmission. We proved that the maximum feeder power depends on the OFDM average power, not on the peak power by analyzing characteristics of OFDM signals and evaluating relationship between impressed pulse voltages and discharge voltages of the feeder.View full abstractDownload PDF (431K) -
Hiroyuki HAMAZUMI, Koichiro IMAMURA, Kohei KANBARA, Akihiro YASUDA, Ka ...Article type: Article
Session ID: ROFT2002-56
Published: May 24, 2002
Released on J-STAGE: June 23, 2017
CONFERENCE PROCEEDINGS FREE ACCESSWhen configuring a SFN (Single Frequency Network) using broadcast-wave relay for digital terrestrial broadcasting, coupling loop interference (CLI), from the transmitting antenna to the receiving antenna, have to be suppressed in a relay station. This paper describes field trials of a CLI canceller carried out at Himeji relay station that suffers a CLI of large delay spread, and the cascade connection of Hokudan-Tarumi and Himeji relay stations. These results showed usefulness of the canceller in broadcast-wave relay stations on a SFN.View full abstractDownload PDF (606K) -
Shigehiro Yamawake, Kenji Komuro, Atsushi InoguchiArticle type: Article
Session ID: ROFT2002-57
Published: May 24, 2002
Released on J-STAGE: June 23, 2017
CONFERENCE PROCEEDINGS FREE ACCESSIn TV transmitting equipment, various redundant systems have been proposed. At introducing digital broadcasting system, the system which an output power is not reduced at the time of equipment failure or maintenance works is required to avoid coverage reduction by the cliff effect. Since broadcasters have to install both analog and digital transmitters at the simulcasting period, small footprint system is required. The N+l standby transmitter system is developed to meet these demands. In this paper, the composition and feature of this system is presented.View full abstractDownload PDF (623K) -
Haruo TAKEDA, Akio FUKUCHI, Kazuyoshi ENOMOTO, Kenji KOMUROArticle type: Article
Session ID: ROFT2002-58
Published: May 24, 2002
Released on J-STAGE: June 23, 2017
CONFERENCE PROCEEDINGS FREE ACCESSHigh linearity performance is required for a digital terrestrial television transmitter. Many methods for correction and analyzing of power amplifier distortions were reported. In transmitter distortions, there are non-linear distortion in time-domain and linear distortion in frequency-domain. Each distortion has amplitude and phase components. Therefore, the correction processes require vector calculations with digital signal processor. Also, it is effective to generate compensation coefficients automatically, and to update the coefficients adaptively. This paper shows consideration points for the designing of an adaptive digital corrector.View full abstractDownload PDF (576K) -
Article type: Appendix
Pages App1-
Published: May 24, 2002
Released on J-STAGE: June 23, 2017
CONFERENCE PROCEEDINGS FREE ACCESSDownload PDF (74K) -
Article type: Appendix
Pages App2-
Published: May 24, 2002
Released on J-STAGE: June 23, 2017
CONFERENCE PROCEEDINGS FREE ACCESSDownload PDF (74K)
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