| 摘要 |
PURPOSE: An input filter circuit of a tuner is provided to prevent a signal from degrading due to a band below a selected band by installing a switching unit blocking a band below the selected band. CONSTITUTION: An input filter(31) blocks a low high frequency signal inputted by the antenna and passes only the high frequency signal. A low noise amplifier(32) amplifies the high frequency signal passed through the input filter. A switching unit(33) reduces band below the high frequency signal band selected in the input filter. A stabilizing portion(34) stabilizes the operation of the switching unit. The switching unit selects VHF-L and UHF bands in the input filter. The selected signal of the VHF-L band is connected to a coupling condenser of the input filter through a third condenser, a first resistance connected in parallel in the first condenser, a first diode, and a third coil. |
