| 摘要 |
<p>PROBLEM TO BE SOLVED: To distribute a high frequency signal without causing deterioration in the noise figure of a tuner. SOLUTION: A high frequency amplifier 1 that receives a high frequency signal from an antenna 8 amplifies the high frequency signal and distributes the amplified signal to 1st, 2nd filters 2, 3 and an RF modulator 7 respectively. A mixer 4 mixes the high frequency signal distributed to the filters 2, 3 with local frequencies to provide an output of an intermediate frequency signal finally. On the other hand, the high frequency signal distributed to the RF modulator, when the RF modulator 7 is inactive, passes through the RF modulator 7 without receiving any modification as an external output.</p> |
