TUNER AND MOBILE DEVICE USING THE SAME

摘要

A tuner has an input terminal, to which a high-frequency signal containing a first high-frequency signal having a first frequency and a second high-frequency having a second frequency and a higher level than that of the first signal is inputted. This tuner includes a first filter connected with the input terminal for passing the signal of the first frequency and for attenuating the signal of the second frequency, a high-frequency amplifier connected with the output of the first filter, a second filter having an input connected with the output of the high-frequency amplifier for passing the signal of the first frequency and for attenuating the signal of the second frequency, a local oscillator, and a mixer for mixing the output of the high-frequency amplifier and the output of the local oscillator. This tuner has a high reception sensitivity even in the presence of a high-power interfering signal close to a reception band and even in a weak electric field.