Renesas Electronics Corporation

Kazuhiro Kijima

Wataru Naito

Noriyoshi Izumi

An IF filter band-limits an intermediate frequency signal outputted from a mixer. An AFC unit controls the oscillation frequency of a PLL so that the frequency of the intermediate frequency signal is a predetermined frequency. When the AFC unit controls the oscillation frequency of the PLL, a band control unit controls the passing characteristic of the IF filter to the passing characteristic of a wide band, and after the completion of the control, controls the passing characteristic of the IF filter to the passing characteristic of a narrow band. A frequency correction unit refers to a filter information storage unit, and corrects the oscillation frequency controlled by the AFC unit according to the difference between the center frequency of the passband of the passing characteristic of the wide band and the center frequency of the passband of the passing characteristic of the narrow band.

Radio receiver and intermediate frequency signal generation method

According to one embodiment, a radio communication deviceincludes a variable frequency dividerthat divides a frequency of a reference clock REFCLK and outputs a frequency divided clock DCLK; a controllerthat controls a frequency dividing ratio of the variable frequency dividerso that an integral multiple of a frequency of the frequency divided clock DCLK is not included in a frequency band of a high-frequency signal that has been received from outside by radio; and a DCDC converterthat performs a switching operation in synchronization with the frequency divided clock DCLK to generate an output voltage Vout obtained by stepping down an input voltage Vin.

Growing community of inventors

Tokyo, Japan

Kazuhiro Kijima