Sharp Kabushiki Kaisha Corporation

Motohisa Nishina

Masahiro Kato

A control portion detects the presence or absence of a pulse signal provided from a satellite broadcast receiver through a port PO to output a control signal PDOUT. In accordance with control signal PDOUT, a power supply circuit stops a supply of one of a power supply potential BIASfed to LNAA and a power supply potential BIASfed to LNAB. Therefore, the power consumption in an LNB designed for multi-satellite can be reduced and even a satellite broadcast receiver having a small current-supply capability can be connected. In this way, a low noise block down converter for multi-satellite with lower power consumption can be provided.

Satellite broadcast receiving converter with lower power consumption

A first printed circuit board is attached to an upper surface of a chassis, and a second printed circuit board is attached to a lower surface of the chassis. The chassis has a thickness of a certain degree, which can reduce a mutual effect of first and second local oscillators, and can suppress occurrence of a spurious signal. Thus, a satellite broadcast receiving device can be provided in which the mutual effect of two local oscillating circuits can be reduced and thus occurrence of a spurious signal is suppressed.

Satellite broadcast receiving device having two local oscillation circuits and reduced spurious signal

In a signal processing circuit of an LNB (Low Noise Block down converter), a power supply circuit is driven by DC voltage applied from four tuners via four signal input/output terminals to generate supply voltage for the LNB and equally distribute consumption current of the LNB among the four signal input/output terminals. Even if the level of the DC voltage from the four tuners is changed, currents of the same value flow through the four signal input/output terminals. Therefore, there is less noise compared with the conventional circuit having a signal input/output terminal allowing current to flow that varies.

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Higashihiroshima, Japan

Motohisa Nishina