| 摘要 |
<p>PROBLEM TO BE SOLVED: To smoothly execute restoration of a carrier even when a frequency offset is considerably large by shifting frequency in an opposite direction by a prescribed frequency so as to conduct frequency conversion. SOLUTION: In order to correct an IF signal of a double conversion tuner 2, the frequency is shifted in the opposite direction to the frequency deviation. In this case, the frequency of an output signal LO2 of a VCO 28 fed to a tuner 2 is adjusted at system-on. Furthermore, a local oscillating signal of an NCO 58 is adjusted. An IF signal is in existence within a band by a SAW filter 4 by tuning the frequency so as to shift the frequency fed to the tuner 2 in an opposite direction by the signal LO2.</p> |
