Abstract: The invention provides a receiving system and a transmitting system capable of decreasing an offset between differential signals and between quadrature signals and improving a manufacturing yield and a semiconductor integrated circuit device for processing a wireless communication signal having therein the systems. A receiving system includes: a local oscillator for generating an oscillation signal in a desired frequency; a 90-degree phase-shifting circuit for generating a signal by shifting a phase of the oscillation signal output from the local oscillator by 90 degrees; a first mixer for mixing one of differential reception signals with an output signal of the first 90-degree phase-shifting circuit and outputting frequency-converted differential signals; and a second mixer for mixing another one of the differential reception signals with an output signal of the local oscillator and outputting frequency-converted differential signals.

Abstract: As the gain control amplifiers for amplifying the reception signal, the step amplifiers are used. Two sets of these step amplifiers are provided and are then controlled to be used alternately. When switching of the gain occurs, after the gain is switched with the step amplifier not operated and offset is cancelled, the amplifier to which the reception signal is inputted is switched. Accordingly, the step amplifier can be used as the gain control amplifier for amplifying the reception signal to provide almost constant power consumption even when the gain is changed depending on the intensity of reception signal in the semiconductor integrated circuit device for communication to form a wireless communication system of dual-mode or more modes including the W-CDMA system. As a result, the operation life of battery, namely, the reception waiting period and communication period by single charging process can be expanded.

Abstract: As the gain control amplifiers for amplifying the reception signal, the step amplifiers are used. Two sets of these step amplifiers are provided and are then controlled to be used alternately. When switching of the gain occurs, after the gain is switched with the step amplifier not operated and offset is cancelled, the amplifier to which the reception signal is inputted is switched. Accordingly, the step amplifier can be used as the gain control amplifier for amplifying the reception signal to provide almost constant power consumption even when the gain is changed depending on the intensity of reception signal in the semiconductor integrated circuit device for communication to form a wireless communication system of dual-mode or more modes including the W-CDMA system. As a result, the operation life of battery, namely, the reception waiting period and communication period by single charging process can be expanded.

Abstract: The invention provides a receiving system and a transmitting system capable of decreasing an offset between differential signals and between quadrature signals and improving a manufacturing yield and a semiconductor integrated circuit device for processing a wireless communication signal having therein the systems. A receiving system includes: a local oscillator for generating an oscillation signal in a desired frequency; a 90-degree phase-shifting circuit for generating a signal by shifting a phase of the oscillation signal output from the local oscillator by 90 degrees; a first mixer for mixing one of differential reception signals with an output signal of the first 90-degree phase-shifting circuit and outputting frequency-converted differential signals; and a second mixer for mixing another one of the differential reception signals with an output signal of the local oscillator and outputting frequency-converted differential signals.

Abstract: As the gain control amplifiers for amplifying the reception signal, the step amplifiers are used. Two sets of these step amplifiers are provided and are then controlled to be used alternately. When switching of the gain occurs, after the gain is switched with the step amplifier not operated and offset is cancelled, the amplifier to which the reception signal is inputted is switched. Accordingly, the step amplifier can be used as the gain control amplifier for amplifying the reception signal to provide almost constant power consumption even when the gain is changed depending on the intensity of reception signal in the semiconductor integrated circuit device for communication to form a wireless communication system of dual-mode or more modes including the W-CDMA system. As a result, the operation life of battery, namely, the reception waiting period and communication period by single charging process can be expanded.