Abstract: A radio signal receiver includes an input for receiving an input signal having an input carrier frequency modulated by a payload signal to be detected. A frequency converter changes the carrier frequency of the input signal and produces an intermediate signal that is an image of the input signal, and has a carrier frequency equal to an intermediate frequency. A filter circuit filters the intermediate signal. A demodulator eliminates a component, with a frequency equal to the intermediate frequency, from the filtered intermediate frequency, and produces the payload signal. The receiver also includes a detection circuit to produce a level signal representative of a level of the payload signal. A control circuit applies a control signal representative of the level signal to a control input of the frequency converter, the filter circuit and the demodulator.

Abstract: A radio signal receiver includes an input for receiving an input signal having an input carrier frequency modulated by a payload signal to be detected. A frequency converter changes the carrier frequency of the input signal and produce an intermediate signal that is an image of the input signal, and has a carrier frequency equal to an intermediate frequency. A filter circuit filters the intermediate signal. A demodulator eliminates a component, with a frequency equal to the intermediate frequency, from the filtered intermediate frequency, and produces the payload signal. The receiver also includes a detection circuit to produce a level signal representative of a level of the payload signal. a control circuit to apply a control signal representative of the level signal to a control input of the frequency converter, the filter circuit and the demodulator.

Abstract: A direct conversion type of frequency transposition device includes a transconductor block receiving the input signal and a current switching block connected to the output from the device. At least the common mode (Iif1+Iif2) is servocontrolled to static output currents from the frequency transposition device on a current proportional to a reference current (Iref) and independent of the static output currents from the transconductor block.

Abstract: A transconductance stage includes at least one principal bipolar transistor having a base linked to an input terminal, a collector linked to an output terminal, and an emitter linked to a supply terminal through a resistor. At least one bipolar compensation transistor is connected in parallel to the principal transistor and linked without going through the resistor to the supply terminal. The value RE of the resistance is chosen so that RE*I0>VT/2, where VT is the thermal voltage and I0 is the quiescent current of the principal transistor.

Abstract: A frequency transposition device includes a current switching circuit with two differential pairs of transistors being controlled by a local oscillator signal. In a current switching circuit calibration mode, the local oscillator is rendered inactive and the two pairs of transistors are calibrated in succession by zeroing the ground path current of one of the pairs of transistors not undergoing calibration, and by setting the voltage difference applied to the bases of the transistors of the pair of transistors undergoing calibration. This is done until the output voltage of the frequency transposition device is zeroed to within a predetermined accuracy. The base voltage difference obtained is stored after calibration. In a normal operating mode the local oscillator is rendered active, and the two stored voltage differences are applied to the respective bases of the two differential pairs of transistors.

Abstract: A direct conversion type of frequency transposition device includes a transconductor block receiving the input signal and a current switching block connected to the output from the device. At least the common mode (Iif1+Iif2) is servocontrolled to static output currents from the frequency transposition device on a current proportional to a reference current (Iref) and independent of the static output currents from the transconductor block.

Abstract: A transconductance stage includes at least one principal bipolar transistor having a base linked to an input terminal, a collector linked to an output terminal, and an emitter linked to a supply terminal through a resistor. At least one bipolar compensation transistor is connected in parallel to the principal transistor and linked without going through the resistor to the supply terminal. The value RE of the resistance is chosen so that RE*I0>VT/2, where VT is the thermal voltage and I0 is the quiescent current of the principal transistor.