摘要:
In a broadcast receiving system, a first antenna receives a broadcast signal of a first frequency band and a second antenna receives a signal of a second frequency band different from the first frequency band. A frequency conversion unit converts the signal of the second frequency band into a second signal of the first frequency band. A selection unit selects one of the broadcast signal output from the first antenna and the second signal output from the frequency conversion unit. A demodulation unit demodulates the one of the broadcast signal and the second signal selected by the selection unit.
摘要:
A CATV tuner apparatus includes a first low-noise amplifier which amplifies a level of an input signal received at an input terminal, the first low-noise amplifier having an adequately small noise figure to allow the received input signal to be amplified with no substantial degradation of a carrier-to-noise ratio of the input signal. An automatic gain control detects the level of the signal amplified by the first low-noise amplifier and adjusts an amplitude of the signal before passing the signal through the automatic gain control. A band-pass filter eliminates out-of-band signal components from the signal received from the automatic gain control and passes only in-band signal components through the band-pass filter. A second low-noise amplifier amplifies a level of the signal received from the band-pass filter. A frequency synthesizer produces an intermediate frequency signal at an output terminal through a multiplication of a frequency of the signal, amplified by the second low-noise amplifier, by an oscillation frequency.
摘要:
An integral type flat antenna provided with a converter function includes an antenna element having a feeding point and an integrally formed multilayered substrate for supporting the antenna element thereon. The multilayered substrate includes a grounding plane layer on which the antenna element is mounted, a first insulating layer provided below the grounding plane layer, a second insulating layer positioned below the first insulating layer and provided with a frequency conversion circuit for carrying out a converter function on frequency of received signals, the frequency conversion circuit having a signal input portion which is positioned at one end of the second insulating layer, and a conducting layer provided between the first and second insulating layers for connecting the feeding point of the antenna element to the signal input section of the frequency conversion circuit.
摘要:
The present invention relates to shield structure of electronic device in which a base board on which high-frequency circuit blocks are mounted is housed in a conductive case thereby to be shielded. A notch is provided for the base board, and a cut-down piece is provided for the conductive case correspondingly to the notch. Hereby, erroneous insertion in which the insertion direction of the base board is wrong can be eliminated. Further, the insertion working of the base board can be readily performed, and productivity can be improved. By removing the useless space of the base board, high-density mounting can be realized, and the whole of the base board has the sufficient shield effect.
摘要:
In a broadcast receiving system, a first antenna receives a broadcast signal of a first frequency band and a second antenna receives a signal of a second frequency band different from the first frequency band. A frequency conversion unit converts the signal of the second frequency band into a second signal of the first frequency band. A selection unit selects one of the broadcast signal output from the first antenna and the second signal output from the frequency conversion unit. A demodulation unit demodulates the one of the broadcast signal and the second signal selected by the selection unit.