Abstract: First and second waveguides which have respective axes thereof arranged parallel to each other are respectively held by dielectric feeders. A projection wall or a thick wall is formed as a correction part on a front surface of a waterproof cover which covers radiation parts of the dielectric feeders. Due to such a constitution, when radio waves transmitted from neighboring first and second satellites are converged by a reflector and are incident on the inside of respective waveguides, it is possible to delay a phase of radio waves which pass the waterproof cover by the correction part (projection wall or thick wall) so that it is possible to adjust such that radiation patterns of radio waves which are incident on the respective waveguides are reflected on a common portion of the reflector whereby the required reflector can be miniaturized.

Abstract: The bandwidth of the band pass filter is to be kept narrow to prevent C/N deterioration, and yet the video carrier and the audio carrier on the final output channel are to be maintained at the same level even if its center frequency deviates from the design value. A double frequency converter is provided with a first mixer for frequency conversion of input signals with first local oscillation signals into first intermediate frequency signals; a second mixer for frequency conversion of the first intermediate frequency signals into output signals with second local oscillation signals; and a band pass filter disposed between the first mixer and the second mixer, wherein the frequency of the first local oscillation signals and that of the second local oscillation signals can be shifted by the same frequency.

Abstract: First and second waveguides which have respective axes thereof arranged parallel to each other are respectively held by dielectric feeders. A projection wall or a thick wall is formed as a correction part on a front surface of a waterproof cover which covers radiation parts of the dielectric feeders. Due to such a constitution, when radio waves transmitted from neighboring first and second satellites are converged by a reflector and are incident on the inside of respective waveguides, it is possible to delay a phase of radio waves which pass the waterproof cover by the correction part (projection wall or thick wall) so that it is possible to adjust such that radiation patterns of radio waves which are incident on the respective waveguides are reflected on a common portion of the reflector whereby the required reflector can be miniaturized.

Abstract: An oscillator attachment structure which prevents interference by a beat signal caused by mixture of a reference oscillation signal from a PLL circuit and an oscillation signal from an oscillator. A plate conductive rubber plate, electrically connected to a ground conductor, is provided on the lower surface of a circuit board, and the conductive rubber plate is disposed on a ground conductive member of a printed circuit board. The ground conductor and the ground conductive member are electrically connected to each other, and the circuit board can be sufficiently grounded to the PLL circuit on the printed circuit board.

Abstract: In a frequency conversion apparatus, a first frequency conversion section is disposed in a first accommodating site, a second frequency conversion section is disposed in a second accommodating site, two shield plates are interposed between the first accommodating site and the second accommodating site, a first partitioned chamber is formed in the region surrounded by the shield plates, a first power supply line is disposed in the first partitioned chamber. Power is directly supplied from the first power supply line to the first frequency conversion section and the second frequency conversion section. With this arrangement, interference caused by the existence of two local oscillators is reduced without increasing the size of metal cases.