This paper reports the feasibility of optical multiple access networks using subcarrier multiplexing (SCM). The SCM technique enables simple, low cost and flexible multiple access networks, such as video monitoring systems. It is shown that a large capacity monitoring system with more than 400 video monitoring terminals or a wide area monitoring system with 150km transmission length are possible by using the SCM multiple access technique.
Microwave absorbers with a thin structure and wide absorbing band using a lossy artificial dielectric materials have been discussed. The system utilizing aluminium powder/rubber composite were studied and their matching thickness with matching relative band width were experimented and discussed. The absorption properties of the microwave absorber of 0.21cm in thickness and 0.4GHz in bandwidth centered at 9.25GHz is demonstrated as an experimental example.
This Paper describes measured and calculated radiation patterns of the VHF-TV receiving antenna which are made based on the Yagi-Uda antenna, in the case when these elements are removed from the structure. These radiation patterns were obtained using the measurement system which was designed and constructed by the authors, and were calculated by the Moment methods.
Propagation characteristics of millimeter waves in the atmosphere are affected by absorption due to atmospheric gases as well as by scattering and absorption due to rain or snow particles. We have developed an experimental radio link for the statistical study of the propagation characteristics at 100GHz in a short range path. In this report, we give an outline of the facilities used in the propagation experiment.