Masahiro Maki

Calculation of Longitudinal Conversion Loss and Input Impedance for Indoor AC Mains Line Considering High-Speed PLC

The power line communication (PLC) system should be investigated with respect to the influence on electromagnetic environments. Longitudinal conversion loss (LCL) and input impedance are important parameters for evaluating the influence because they are closely related to the radiated, conducted, and inducted emission. An indoor AC mains system consisting of electrical equipment and an AC mains line was modeled by four-port networks, and the LCL and the input impedance were calculated. The parameters of the four-port networks were determined from theory and measurement. The analytical model was examined using a simple network and the results show that the calculated values agreed with the measured ones. The LCL and the input impedance were investigated at the AC mains port in some existing buildings, and the measured results almost agreed with the calculated results derived from the indoor AC mains system model.

Home information wiring system using UTP cable for IEEE1394 and Ethernet systems

IEEE1394 and Ethernet systems are being extensively adopted for data communications equipment, including audiovisual equipment and personal computers. This paper proposes a wiring system that enables the simultaneous transmission of IEEE1394 signals and Ethernet signals along a single UTP-CAT5 cable consisting of four twisted pairs. The requirements of this wiring system were determined by taking into account the specifications of both IEEE1394 and Ethernet systems and the actual domestic environment. Home network adapters were developed to connect IEEE1394 and Ethernet cable to UTP cable. Insertion loss, crosstalk, and eye-diagrams were measured to evaluate the systems performance. The results show that our proposed wiring system is capable of transmitting both the IEEE1394 signal and the Ethernet signal simultaneously at 100 Mbps up to a distance of 100 m along a UTP-CAT5 cable.

Transmission characteristics of a twisted-pair cable for broadband communications

Analysis methods are discussed and used to evaluate the broadband transmission characteristics of the twisted pair cable in the GHz frequency band (e.g., HDMI, IEEE1394, etc.). Aside from the transmission characteristics of the cable used, losses incurred by the interface cards have also to be taken into consideration in the analysis of communication systems, especially for frequencies above 100 MHz.