Sanyo Electric Co., Ltd.

Semiconductor Components Industries, LLC

Sanyo Semiconductor Co., Ltd.

Masaya Suto

Yasuji Saito

Masaaki Taira

A receiving apparatus comprising: a frequency-fluctuation-detection unit to detect a frequency difference between a received and desired signals; a first-undesired-level-detection unit to output as a first-undesired level an amplitude-level-difference between the signals having passed through first-and-second-band-pass filters in the received signals; one or a plurality of second-undesired-level-detection units to output amplitude levels of signals having passed through third-and-fourth-band-pass filters in the received signals as second-and-third-undesired levels, respectively, and output a sum of the second-and-third-undesired levels as a fourth-undesired level; and a determination unit to determine whether an undesired state, where an adjacent-undesired signal is present, occurs according to the fourth-undesired level if an absolute value of the frequency difference is equal to or greater than a predetermined-reference value, and select any one of the first-to-third-undesired levels to be outputted according to at least one of the frequency difference and the fourth-undesired level if determining that the undesired state occurs.

Receiving apparatus

A band-switch control apparatus for an intermediate-frequency filter comprising: an adjacent interference-signal detecting unit for detecting an adjacent interference-signal, having a frequency adjacent to the desired frequency, superimposed on a reception signal having a frequency tuned to a desired frequency; a modulation-degree detecting unit for detecting a modulation degree of the reception signal; a bandwidth selecting unit for selecting a pass bandwidth of the intermediate-frequency filter corresponding to the amplitude of the adjacent interference-signal; and a band-narrowing suppression control unit for selecting a lower limit value of the pass bandwidth of the intermediate-frequency filter corresponding to the demodulation degree, the intermediate-frequency filter for passing, with a variable pass bandwidth, an intermediate-frequency signal obtained by frequency converting the reception signal, and changing the pass bandwidth selected by the bandwidth selecting unit to the lower limit value, if the pass bandwidth selected by the bandwidth selecting unit is smaller than the value.

Band switch control apparatus for intermediate frequency filter

A multipass noise detecting apparatus comprising: a smoothing process unit configured to receive input of a signal corresponding to electric field strength of a received signal and to smooth the signal; a delay process unit configured to delay the signal; an amplifying unit configured to amplify a signal output from the smoothing process unit; a pulse noise determining unit configured to compare a signal output from the delay process unit with a signal output from the amplifying unit to output a pulse noise determining signal indicating a period of presence of pulse noise; and a noise cancel process unit configured to carry out a process for removing pulse noise on the basis of the pulse noise determining signal, the process being applied to the signal output from the delay process unit.

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Maebashi, Japan

Masaya Suto