We have been conducting the research and development on a new-type optical fiber cable for use in measuring ocean information such as salinity and turbidity. The sea trial cable is manufactured and the cable testing is performed in Saiki Bay. This paper describes the design and the transmission characteristics of the nonmetallic optical fiber cable. Measurements of eye pattern and transmission loss are made after suspending the cable from a ship. The optical behavior of the cable during the testing is very stable under high pressure, high tension, and any other external force. Waveform distortion and optical loss change are not observed in all of the six fibers. From the experimental results, it is confirmed that the cable meets design goals and receives practical applications to analog and digital transmission.
In this paper, the theoretical consideration is described on the thin and single layer radio-wave absorber. And the designing chart are drawn accoding to the theoretical formula. The necessary condition are generally as following, that is, the impedance of single layer absorber equal to free space impedance at the boundary surface and the energy is spent perfectly while propagating in the absorber. The experimental results are almost agree-able to the theoretical calculated too, and is compared to the experimental result.
We confirmed that class F tuned mode to the VHF power amplifier using MOS-FET could achieve a higher efficiency performance than the conventional class D tuned mode. The characteristics of both class D mode and class F mode were compared experimentally. For both output power and power efficiency of class F mode was analyzed theoretically and confirmed its superiority.
We developed a new, transformed ring resonator that is grounded and fixed its neutral point to its shield case. With the resonators, a 4-stage BPF was fabricated and tested. Electric power tolerance, voltage tolerance and vibration tolerance of the resonators were better than those of helical resonators. Dimensions and unloaded Q of the resontors were comparable to those of helical resonators.