Abstract: A digital tuner unit receiving a digital signal in a reception channel having a predetermined bandwidth is connected at a subsequent stage of an antenna device containing radiation conductors and varactor diodes. A digital reception signal output from the digital tuner unit is input to a demodulation circuit and subjected to demodulation. An SP level detection unit of the demodulation circuit detects levels of a plurality of spread pilot signals in the bandwidth of the reception channel, and obtains a correction amount for a tuning voltage so that a level difference can be reduced to a predetermined value or less using the correction amount. The SP level detection unit reports the correction amount to an antenna tuning control unit so that the tuning voltage to be supplied to the antenna device can be corrected using the correction amount.

Abstract: A first low-noise amplifier is connected to a first receiving processing unit through a first cable and a bypass circuit is provided in parallel to the first low-noise amplifier so as to bypass the first low-noise amplifier. In the case that the intensity of broadcasting signal is more than a predetermined value, when the C/N is more than a first predetermined value and less than a second predetermined value higher than the first predetermined value, the broadcasting signal is transmitted to the first cable through the first low-noise amplifier, and when the C/N is less than the first predetermined value or more than the second predetermined value, the broadcasting signal is not input to the first low-noise amplifier but transmitted to the first cable through the bypass circuit.

Abstract: An antenna device for television broadcast reception includes an antenna element including a base member and a radiating conductor, and a matching circuit. A feed signal is supplied to the antenna element via the matching circuit. The matching circuit includes a variable capacitance element (varactor diode), a first inductance element connected in parallel to the variable capacitance element, and a second inductance element connected in series with the variable capacitance element. A capacitance value of the variable capacitance element is changed to change a resonant frequency of the antenna element. The variable capacitance element and the first inductance element form a parallel circuit, and a resonance point of the parallel circuit is set to a frequency lower than the resonant frequency of the antenna element. As the resonant frequency increases, the resonance point is shifted to a high-frequency side.

Abstract: An OFDM receiver has four antennas or more for receiving an OFDM modulated high frequency signal, and plural OFDM demodulators for inputting a baseband signal of a time domain thereto on the basis of the high frequency signal and outputting the baseband signal of a frequency domain, wherein the OFDM demodulators are arranged every plural antenna groups with two or more of the antennas as one group, and a signal is diversity-synthesized by a first phase shifter until the baseband signal of the time domain is inputted to each of the OFDM demodulators, and the baseband signal of the frequency domain is diversity-synthesized by a second phase shifter.

Abstract: An antenna device is configured such that a chip antenna is mounted on a circuit substrate including first and second transmission lines, a high-frequency changeover switch, and a bias circuit. First ends of first and second radiation conductors that are wound around a base member of the chip antenna are connected to each other, and variable-capacitance elements are distributed in each of the radiation conductors. When an electrical connection between the input terminal and the output terminal of the high-frequency changeover switch is established, a feeding signal is supplied to the first transmission line to provide a high-band mode. When the electrical connection is disconnected, the feeding signal is supplied to the second transmission line to provide a low-band mode. In either band, a tuning voltage is supplied from the bias circuit to the variable-capacitance elements, whereby the tuning frequency of the antenna device can be changed.

Abstract: A digital tuner unit receiving a digital signal in a reception channel having a predetermined bandwidth is connected at a subsequent stage of an antenna device containing radiation conductors and varactor diodes. A digital reception signal output from the digital tuner unit is input to a demodulation circuit and subjected to demodulation. An SP level detection unit of the demodulation circuit detects levels of a plurality of spread pilot signals in the bandwidth of the reception channel, and obtains a correction amount for a tuning voltage so that a level difference can be reduced to a predetermined value or less using the correction amount. The SP level detection unit reports the correction amount to an antenna tuning control unit so that the tuning voltage to be supplied to the antenna device can be corrected using the correction amount.

Abstract: A first low-noise amplifier is connected to a first receiving processing unit through a first cable and a bypass circuit is provided in parallel to the first low-noise amplifier so as to bypass the first low-noise amplifier. In the case that the intensity of broadcasting signal is more than a predetermined value, when the C/N is more than a first predetermined value and less than a second predetermined value higher than the first predetermined value, the broadcasting signal is transmitted to the first cable through the first low-noise amplifier, and when the C/N is less than the first predetermined value or more than the second predetermined value, the broadcasting signal is not input to the first low-noise amplifier but transmitted to the first cable through the bypass circuit.

Abstract: A delay equalizing unit includes a delay time calculating unit for calculating a plurality of delay times which differ from each other by short time periods and which include the delay time of the delayed wave with respect to the direct wave, so that an OFDM-modulated signal input to path correlation detectors is delayed by the plurality of delay times. A feedback unit causes the amplitude and phase of the negatively fed back direct wave to coincide with the amplitude and phase of the delayed wave input to an adding unit based on the largest of the path correlations, so that the negatively fed back direct wave is delayed by a designated delay time based on which the largest path correlation is determined.

Abstract: A diversity receiving apparatus comprises a plurality of antennas, a plurality of receiving circuits connected to the plurality of antennas, respectively, an adding unit for adding reception signals output from the respective receiving circuits, and a plurality phase shifting units for making phases of the reception signals to be input into the adding unit equal. A level comparing unit, for comparing the levels of the reception signals output from the respective receiving circuits, is provided. Phases of reception signals other than a maximum-level reception signal are controlled so as to have the same phase as the phase of the maximum-level reception signal, and the phase-controlled signals are input into the adding unit.

Abstract: A receiver has an adder for output intermediate-frequency signals of a plurality of receiving blocks, a demodulator for an added intermediate-frequency signal, adjustable reference-signal generator for supplying phase-shifted reference signals to the PLL circuits of the plurality of receiving blocks, and a plurality of switches. The switches are controlled when power is first supplied to the receiver such that the frequency-divided reference signals to the PLL circuits are in phase with one another. The adjustable reference-signal generator, upon tuning on power, is set in the phase-shift adjusted state stored immediately before previously turning off the power.

Abstract: A diversity reception device includes a plurality of antennas. A plurality of receiver circuits are connected to the corresponding antennas. An adder adds the received signals output from the receiver circuits. Phase shifters allow the received signals to be input into the adder in phase with each other. A level comparator unit compares the levels of the received signals output from the receiver circuits. A level variable unit is interposed between each of the receiver circuits and the adder, and is controlled by the level comparator unit. Each of the received signals other than the received signal having the maximum level is relatively attenuated by the corresponding level variable unit in accordance with the difference of the level of the received signal from the maximum level before being input into the adder.

Abstract: An antenna receiver includes a plurality of mixers for frequency-converting signals received by a plurality of antennas into intermediate-frequency signals; a plurality of local oscillators, which correspond to the plurality of mixers and which supply local oscillation signals having the same frequency to the mixers; a plurality of PLL circuits, which correspond to the plurality of local oscillators and which set the frequency of the local oscillation signals; and an adder for adding the intermediate-frequency signals output from the mixers. The phases of reference signals supplied to the PLL circuits can be changed independently from each other.

Abstract: There is provided a diversity receiving apparatus capable of preventing a reduction in C/N ratio when phases of signals to be input into adding means are matched for diversity synthesis and of easily taking synchronization during demodulation.

Abstract: A diversity reception device includes a plurality of antennas. A plurality of receiver circuits are connected to the corresponding antennas. An adder adds the received signals output from the receiver circuits. Phase shifters allow the received signals to be input into the adder in phase with each other. A level comparator unit compares the levels of the received signals output from the receiver circuits. A level variable unit is interposed between each of the receiver circuits and the adder, and is controlled by the level comparator unit. Each of the received signals other than the received signal having the maximum level is relatively attenuated by the corresponding level variable unit in accordance with the difference of the level of the received signal from the maximum level before being input into the adder.

Abstract: A delay equalizing unit includes a delay time calculating unit for calculating a plurality of delay times which differ from each other by short time periods and which include the delay time of the delayed wave with respect to the direct wave, so that an OFDM-modulated signal input to path correlation detectors is delayed by the plurality of delay times. A feedback unit causes the amplitude and phase of the negatively fed back direct wave to coincide with the amplitude and phase of the delayed wave input to an adding unit based on the largest of the path correlations, so that the negatively fed back direct wave is delayed by a designated delay time based on which the largest path correlation is determined.

Abstract: An OFDM receiver has four antennas or more for receiving an OFDM modulated high frequency signal, and plural OFDM demodulators for inputting a base band signal of a time area thereto on the basis of the high frequency signal and outputting the base band signal of a frequency area, wherein the OFDM demodulators are arranged every plural antenna groups with two or more of the antennas as one group, and a signal is diversity-synthesized by a first phase shifter until the base band signal of the time area is inputted to each of the OFDM demodulators, and the base band signal of the frequency area is diversity-synthesized by a second phase shifter.

Abstract: A receiver has an adder for output intermediate-frequency signals of a plurality of receiving blocks, a demodulator for an added intermediate-frequency signal, adjustable reference-signal generator for supplying phase-shifted reference signals to the PLL circuits of the plurality of receiving blocks, and a plurality of switches. The switches are controlled when power is first supplied to the receiver such that the frequency-divided reference signals to the PLL circuits are in phase with one another. The adjustable reference-signal generator, upon tuning on power, is set in the phase-shift adjusted state stored immediately before previously turning off the power.

Abstract: A delay equalizing unit includes an adding unit to which an OFDM-modulated signal is input, and a feedback unit for negatively feeding back a direct wave output from the adding unit to the adding unit. The direct wave negatively fed back by the feedback unit is delayed by the delay time of a delayed wave with respect to the direct wave, and is corrected so that the amplitude and phase of the direct wave negatively fed back by the feedback unit are equal to the amplitude and phase of the delayed wave input to the adding unit.

Abstract: An antenna receiver includes a plurality of mixers for frequency-converting signals received by a plurality of antennas into intermediate-frequency signals; a plurality of local oscillators, which correspond to the plurality of mixers and which supply local oscillation signals having the same frequency to the mixers; a plurality of PLL circuits, which correspond to the plurality of local oscillators and which set the frequency of the local oscillation signals; and an adder for adding the intermediate-frequency signals output from the mixers. The phases of reference signals supplied to the PLL circuits can be changed independently from each other.

Abstract: An OFDM receiving apparatus includes a plurality of first mixers for frequency-converting OFDM modulation signals received by a plurality of antennas, respectively, which are spaced from each other, into a first intermediate-frequency signal; a local oscillation device for supplying a first local oscillation signal to each of the first mixers; an adder for combining the first intermediate-frequency signals; an A/D converter for converting the combined first intermediate-frequency signal into a digital signal; an OFDM demodulation device for OFDM-demodulating the digital signal; and a phase control device for performing phase setting of the first local oscillation signal supplied to each of the first mixers for the purpose of causing the power of the combined OFDM modulation signal to reach a predetermined level or higher.