RECEIVER FOR SATELLITE DIGITAL MULTIMEDIA BROADCASTING INCLUDING BYPASS CIRCUIT

摘要

A satellite DMB(Digital Multimedia Broadcasting) receiving with a bypass circuit is provided to selectively filter or bypass an intermediate frequency band in response to an input signal band and improve the performance of the receiver by reducing noise and loss of load. A satellite DMB receiver with a bypass circuit includes an RF(Radio Frequency) stage(210), an IF(Intermediate Frequency) stage(220), and a frequency supply(230). The RF stage converts a DMB frequency received from an antenna into an intermediate frequency. The IF stage converts the intermediate frequency into a base-band signal. The frequency supply supplies a frequency such that the signal received by the RF stage is converted into the intermediate frequency. The IF stage includes a first receiving unit(220a) and a second receiving unit. The first receiving unit includes a first bypass filter(221a) having a first filter and a first switch connected in parallel and a first low noise amplifier(222a) and forms an I-channel. The second receiving unit includes a second bypass filter(221b) having a second filter and a second switch connected in parallel and a second low noise amplifier(222b) and forms a Q-channel. When the first and second switches are on, the intermediate frequency of the I/Q channel bypasses. When the first and second switches are off, the intermediate frequency of the I/Q channel are filtered by the first and second filters.