Tasuku Teshirogi

A slot‐array antenna on a coaxial cylinder with a circularly polarized conical beam

In mobile communication, omnidirectional directivity and circular polarization are convenient properties because when they are used, acquisition and track operations for direction and polarization are not needed. As an antenna which has such properties, we developed a slot-array antenna on an oversize coaxial cylinder. This array antenna has less loss than microstrip arrays because energy is transported to each slot in the oversize coaxial waveguide. Also we can shape the beam in the vertical plane by controlling the size and position of slots. We developed cosecant and conical beam antennas. They are scale model antennas for respectively indoor communication by millimeter waves and mobile satellite communications. We show the performance of these antennas.

ETS-II Experiments Part II: Earth Station Facilities

A part of the Earth station at the Kashima Branch of the Radio Research Laboratories has a highly sensitive receiving system newly designed for receiving 3 coherent and weak beacon signals transmitted from the Engineering Test Satellite Type-II (ETS-II) of Japan and obtaining propagation data on quasimillimeter and millimeter wavelengths. The ground system includes a main receiving station which has a 10-m diameter antenna for multifrequencies, highly sensitive receivers, a rain radar, which has many unique functions, a radiometer, meteorological instruments, and data processing computers. The facilities of the main receiving station for ETS-II propagation experiments, except for the rain radar, are described.