We developed a small. high-Performance output-filter composed of dielectric resonators made of dielectric material Whose relative dielectric constant is about 80. The output-filter can be comprised in TV broadcasting repeater. Its volume is a quater of the conventional one composed of helical resonators, and it has higher performance.
We have developed small-sized video transmission equipment for ITV (Industrial Television) system. We adopted FM-FDM optical passive network as video transmission method. The method enabled the system to dolong distance video transmissions from various points by a single optical fiber. we mainly examined the following items. (1) The performance (2) The structure (3) The rise of temperature in the box
The 1992's World Administrative Radio Conference(WARC'92) made an allocation in the bands 21.4-22.0 GHZ in Region 1 and 3 to the broadcasting satellite service(BSS). To establish this new BSS system, mitigation technology of rain attenuation is important. As one of that technologies, adaptive satellite power control using satellite-borne multi-beam antenna has been proposed. In this paper, the effect of this dynamic satellite power control method is evaluated quantitatively by using spatial correlation characteristics of rainfall rates. If the power is controlled according to the attenuation at the center of each beam, the benefit of the power control is confined to the area near that center of the beam.
WARC'92 made an allocation in the bands 21.4-22.0 GHZ in region 1 and 3 to the broadcasting satellite service. To establish this new BSS system, the modulation method which has high utilization efficiency of frequency is important. The 16QAM(quadrature amplitude modulation) has high efficiency, although it was not used in BSS because of TWT's non-linearity. In this paper, the optimum modulation method which gives maximum bit rate in the 21GHz BSS is described, and countermeasure for the non-linearity by pre-distortion circuit is also mentioned. As a result of computer simulation, the C/N degradation was 1.6 dB with pre-distortion circuit and modification of the signal constellation.
The possibility of digital satellite broadcasting services has been discussing in ITU-R for the modernization of the WARC-BS Plan. In the discussion, the maximum transmission bit rate is one of the most important subjects. It depends on a variety of parameters, such as satellite EIRP, channel bandwidth, and service availability. A generalized method for estimating the maximum transmission bit rate for various kinds of satellite systems is proposed assuming a high power TWT, an output multiplexer and QPSK with concatenated codes. Practical transmission capacities in some satellite transponders are also estimated for designing a new digital satellite broadcasting systems as well as for contributing ITU-R.
In order to permit the transmission and reception of full-motion video on trains, boats, planes, and other mobile structures, it is necessary to develop technology to utilize both broadcasting and communications satellites. In April 1991, Fuji Television, established the "Mobile Satellite Transmission and Reception Research Consortium" and began working together to develop technology to permit the mobile transmission and reception of television broadcasts via communications satellite. Here we introduce these systems.