| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a receiver which, thanks to an increased band of a PLL loop filter, greatly improves the phase noise performance of a local oscillator and also improves adjacent channel selection performance. <P>SOLUTION: In a radio receiver, a receive signal and a local signal which is output from a local oscillator are mixed by a mixer, and a generated intermediate frequency (IF) signal is selected by a band-pass filter before being demodulated. The local oscillator is composed to switch a local signal from one to another which are at intervals of n times the channel frequency interval of a receive signal (n=integer equal to or greater than 3) before outputting it. The band-pass filter is composed to switch the center frequency of a pass band from one to another depending on a channel through which the receive signal is to be received. <P>COPYRIGHT: (C)2013,JPO&INPIT |
