Synthesizer receiver

A synthesizer receiver in which a local oscillation frequency is changed by changing a frequency dividing ratio of a variable frequency dividing circuit in a phase-locked loop circuit to perform a seeking operation of a broadcast band and said seeking operation is stopped by stopping a change of said frequency dividing ratio, said receiver comprising:

• a variable bandpass filter having a variable passband width to which an intermediate frequency signal is supplied;
• a filter for extracting a signal having a frequency component when an adjacent broadcast wave signal is received from a demodulation output obtained by demodulating said intermediate frequency signal;
• a first detection circuit for detecting a level of an output signal of said variable bandpass filter;
• a second detection circuit for detecting a received electric field intensity based on the output signal of said variable bandpass filter;
• a frequency counter for counting a frequency of the output signal of said variable bandpass filter;
• and
• a control circuit to which an output signal according to the detected output of said second detection circuit and a count output of said frequency counter is supplied,
• wherein:
• a detected output of said first detection circuit is supplied to said variable bandpass filter as the control signal for controlling said width,
• said control circuit performs processing including the steps of:
• allowing a detection output signal of said first detection circuit to control the passband width of said variable bandpass filter to thereby check a detected output of said second detection circuit during execution of a seek operation;
• controlling the passband width of said variable bandpass filter to be switched to a wide band when the detected output of said second detection circuit indicates that the received electric field intensity is equal to or greater than a predetermined value, and determining whether the detected output is tuned to a desired broadcast wave signal based on the counter value of said frequency counter;
• and
• controlling said seek operation to stop when the detected result indicates that the detected output is tuned to the desired broadcast wave signal.