A new method of exciting a two-wire spiral antenna from two off-center sources is proposed in order to obtain the polarization diversity. It is found both numerically and experimentally that as the locations of two sources are shifted from the center of the spiral towards the arm ends, the radiation wave changes from a right-hand to a left-hand circularly polarized wave, by way of a stage in which a linearly polarized wave is produced. On the basis of the obtained results, the frequency characteristics of a spiral antenna with two fixed sources are investigated. It is found that the spiral antenna radiates a right-hand circularly polarized wave at a frequency of f" and a left-hand circularly polarized wave at a frequency of 2f".

This paper describes Japanese-English translation of weather reports by ISOBAR. Recently, there have been developed a lot of automatic translation systems, either operational or experimental. In the domain of meteorological reports, TAUM-METEO (English-French) is the best-known operational system, which is classified as one of the transfer systems. Our translation by ISOBAR is still experimental, but its most remarkable feature is that target language (TL) sentences are generated only from interlingual meaning representations of input source language (SL) sentences. That is, our system has no transfer component. In this approach, one sentence can be translated into plural TL sentences which are in the paraphrase relation. During semantic processing of SL sentences, ISOBAR, unlike Wilks' model, is designed to reject definitely such sentences as are semantically anomalous or contradictory to its knowledge. We discuss several merits and demerits of this approach, and show some experimental results in ISOBAR.

Excitation amplitude and phase coefficients of array elements are designed for the use of a primary feed reflector antenna with the intension of improving its beam scanning characteristics. Special attention is paid for beam isolation between two adjacent beams in an area coverage beam arrangement. After several method are compared, it is pointed out that coefficients determined in terms of aperture distribution are effective for compensating gain reduction in widely scanned angle, while they can not control beam isolation. Beam isolation, on the other hand, is effectively improved by designing array coefficients so as to arrange null points of the far field pattern on a circle with its beam direction centered. In this method, number of null points and radius of the circle are determined to get higher beam isolation. Number of null points may be set greater than that of elements, provided null points in the sense of a least mean square are also admissible. A simple parabola with offset angle of 45, fed by 9-horn array thus designed, can scan its beam beyond 10 halfpower beam width, keeping no less than 27 dB isolation between beams with spacing of about 2.0 halfpower beam width apart.

A new type of Josephson NDRO memory cell is presented, where a sense gate is coupled directly to the memory part, instead of the conventional magnetic coupling scheme. The memory cell operates without complexity of the sequence of signals, and the operation margin is shown to be 20%.

For use as radiation-resistant fibers, germanium-free optical fiber performs with fluorine-doped cladding were prepared by the PCVD process using various kinds of fluorine raw materials. As a result, numerical apertures as high as 0.3 were attained by using suitable fluorine raw materials.

High efficient coding of monochrome images using new implementation of Rademacher transform is described. A computer simulation has been performed to evaluate performance of the system. The system proposed here shows less sensitivity to type of pictures.

Receiver sensitivity improvements as much as 16.4 dB and 4.1 dB over direct detection and ASK heterodyne detection, respectively, have been realized in 32 Mb/s PSK heterodyne detection simulation experiments using a 1.3µm wavelength laser diode.

A multiple fiber connector with an alignment hole for a multiple extrusion unit is proposed. An average connector loss of 0.27 dB is achieved by employing index matching oil. Furthermore, the cause of the loss is evaluated, and it is shown that the calculated losses agree with the experimental values.

Radiation properties of double-choked circular waveguides fed by TE-11 mode are found experimentally to be sensitive to the choke positions. By properly selecting the load position, better cross-polar properties can be expected.