Abstract: A non-contact rotating coupler for transmitting a signal through coupling capacitances formed between opposite coupling plates arranged apart from each other. In the coupling plate, an inductance for causing a parallel resonance in a signal frequency band with a stray capacity existing between a grounded conductor and a non-grounded conductor is connected between a junction point of a resistor and a capacitor and the grounded conductor or between the non-grounded conductor and the grounded conductor, thereby reducing a coupling loss.

Abstract: A receiving antenna apparatus for receiving broadcast by satellite and adapted for mounting on a mobile body in which radio wave interruption tends to occur by obstacles, attains high-speed automatic tracking function capable of catching the satellite again in a short time just after cutting off of radio waves. In the receiving antenna apparatus, an incoming direction of radio waves is roughly detected to limit a search area and then a gain of the tuners is reduced to a value in the tracking control capable of detecting a peak and confirming a main lobe in accordance with power level of the received signal, so that a narrow and fine search may be made only in the limited search area. The antenna apparatus includes a gain setting device for varying gains of AGC of the tuners.

Abstract: The present invention relates to an antenna apparatus for a moving object. It comprises a casing mountable on a moving object and a base plate rotatably supported for rotation about a first rotary shaft which is fixed to the casing. A first drive is provided for rotatably driving the base plate about the first rotary shaft. An antenna unit includes a first antenna plate having a predetermined first beam axis, a second antenna plate having a predetermined second beam axis and connecting member for connecting the first and second antenna plates, with the first and second beam axes being oriented parallel to each other and with the antenna plates being positioned at a predetermined fixed offset distance between them along a line which is parallel to the first and second beam axes.

Abstract: A satellite broadcast receiving antenna apparatus having an automatic tracking function for mobile bodies subject to radio wave interference due to obstacles is disclosed, in which phase correction circuits are arranged in the stage before a phase difference detection circuit, and the amount of phase shift of the phase correction circuits is adjusted by a CPU in such a manner that the peaks of the received signals are coincident in phase with each other at the time of detection thereof. The amount of phase shift associated with the coincidence is stored in a phase shift amount memory, and phase correction is effected on the amount of phase shift read from the memory is subsequent automatic tracking.

Abstract: A satellite tracking antenna system comprises three or four plane antennas juxtaposed on a single plane. A first and a second antenna are juxtaposed in an azimuth direction, and a phase difference between signals received by these antennas is detected in order to determine a declination of an antenna unit with respect to the satellite as viewed in the azimuth direction. The first and a third antenna are juxtaposed in an elevation direction, and a phase difference between signals received by these antennas is detected to determine a declination of the antenna unit with respect to the satellite as viewed in the elevation direction. The antenna unit is driven so as to reduce these declinations to zero. Stated differently, values of a sine and a cosine function are extracted which have a phase difference between signals received by a pair of antennas as a parameter, and a tangent value representing the ratio therebetween is calculated and is then inversely converted to provide phase difference information.

Abstract: A satellite tracking antenna system comprises three or four plane antennas juxtaposed on a single plane. A first and a second antenna are juxtaposed in an azimuth direction, and a phase difference between signals received by these antennas is detected in order to determine a declination of an antenna unit with respect to the satellite as viewed in the azimuth direction. The first and a third antenna are juxtaposed in an elevation direction, and a phase difference between signals received by these antennas is detected to determine a declination of the antenna unit with respect to the satellite as viewed in the elevation direction. The antenna unit is driven so as to reduce these declinations to zero. Stated differently, values of a sine and a cosine function are extracted which have a phase difference between signals received by a pair of antennas as a parameter, and a tangent value representing the ratio therebetween is calculated and is then inversely converted to provide phase difference information.