Abstract: A receiver device is provided singly capable of applying demodulator circuits with differing frequency characteristics with respective signals of desired frequencies for the demodulator circuits. The receiver device in accordance with the present invention switches between a mode in which a digital signal having a frequency suitable for various signal processes is supplied to a DA converter and a mode in which a digital signal for which the IF frequency is about 30 MHz to 60 MHz is supplied to the DA converter, by using a switch and a wire.

Abstract: A broadcasting satellite receiving converter IC includes a switch circuit and a voltage generating source. Disposed in front of the broadcasting satellite receiving converter IC are two first amplifying circuits which amplify differently polarized BS signals, respectively, and a second amplifying circuit. The switch circuit receives, from a BS tuner, a DC voltage signal for controlling switching of polarized signals to be received, and detects the strength of the received DC voltage signal, thereby determining which of the first amplifying circuits to use. Depending on the strength of the DC voltage signal detected by the switch circuit, the voltage generating source supplies either the first amplifying circuits and the second amplifying circuit with positive and negative voltages through a plurality of terminals.

Abstract: A receiver device is provided singly capable of applying demodulator circuits with differing frequency characteristics with respective signals of desired frequencies for the demodulator circuits. The receiver device in accordance with the present invention switches between a mode in which a digital signal having a frequency suitable for various signal processes is supplied to a DA converter and a mode in which a digital signal for which the IF frequency is about 30 MHz to 60 MHz is supplied to the DA converter, by using a switch and a wire.

Abstract: A frequency converter that performs dual frequency conversion is provided. The frequency converter restricts noise occurrence and enables signal transfer with good linearity. The frequency converter performs dual conversion of a first signal (RF(+) and RF(?)) by using two signals including a second signal (LO1 (+) and LO1 (?)) and a third signal (LO2 (+) and LO2 (?)). Using a balun and an amplifying circuit that performs input/output operations in a single-ended manner, the frequency converter restricts NF degradation. By feeding optimum values of current into the first and second switching circuits and into the amplifying circuit, NF and linearity are optimized. The balun, the amplifying circuit, and the first and second switching circuits are formed on the same semiconductor substrate.

Abstract: A frequency converter that performs dual frequency conversion is provided. The frequency converter restricts noise occurrence and enables signal transfer with good linearity. The frequency converter performs dual conversion of a first signal (RF(+) and RF(?)) by using two signals including a second signal (LO1(+) and LO1(?)) and a third signal (LO2(+) and LO2(?)). Using a balun and an amplifying circuit that performs input/output operations in a single-ended manner, the frequency converter restricts NF degradation. By feeding optimum values of current into the first and second switching circuits and into the amplifying circuit, NF and linearity are optimized. The balun, the amplifying circuit, and the first and second switching circuits are formed on the same semiconductor substrate.