| 摘要 |
A digital broadcasting receiver tuner that demodulates excellently a digital signal by substantially reducing a second local oscillation signal that strays from a second frequency conversion stage to a first frequency conversion stage. The digital broadcasting receiver tuner comprises the first frequency conversion stage for frequency converting a received signal into a first intermediate frequency signal higher than the upper frequency limit the received signal, a first intermediate frequency filter for extracting the first intermediate frequency signal, the second frequency conversion stage for frequency converting the extracted first intermediate frequency signal into a second intermediate frequency signal having a predetermined band included in a frequency range extending from 0 to 30 MHz, a second intermediate frequency filter for extracting the second intermediate frequency signal, and a demodulation stage for demodulating the extracted second intermediate frequency signal, wherein the second frequency conversion stage comprises a frequency mixer of high isolation characteristics. |
