Abstract: The invention relates to a device for frequency conversion, comprising exactly one multi-band mixer (3) with means for transferring a signal (2) that is applied to the signal input of said multi-band mixer (3) from said signal's source frequency band to one out of a plurality of target frequency sub-bands at a time, yielding a transferred signal (4) at the signal output of said multi-band mixer (3), wherein said plurality of target frequency sub-bands defines at least a first and a second target frequency band, and a bank of switchable Variable Gain Amplifiers (VGAs) (5-1, 5-2) for amplifying said transferred signal (4), wherein for each of said target frequency bands, one switchable VGA (5-1, 5-2) is provided that is adapted to said target frequency band and is connected to the signal output of said multi-band mixer (3). The invention also relates to a method for frequency conversion.

Abstract: A method is disclosed for operating a radio frequency transmitter chain component, as is a radio frequency transmitter chain component that operates in accordance with the method. The method includes receiving an input signal to be mixed with a signal output from an oscillator, where the input signal is received through an operational amplifier. The method further includes applying an output of the operational amplifier to an input of a mixing circuit, rectifying the input signal to produce a rectified input signal and controlling a common-mode output voltage of the operational amplifier with the rectified input signal. This process varies the power consumption of the component in a manner that is proportional to a value of the input signal. A further step couples a mixer output signal to an input of a VGA. The component may include both the mixer and the VGA. In the preferred embodiment the input signal and the mixer output signal are differential signals.

Abstract: Disclosed is an RF transmitter circuit (10), as well as a method for operating the circuit. The RF transmitter circuit includes a VGA (20), that includes circuitry for generating a feedback signal, and a temperature compensation block (18) having an input coupled to a gain control signal and an output coupled to an input of the VGA for providing to the VGA a compensated gain control signal. The temperature compensation block further includes a bias input that receives the VGA feedback signal. The VGA feedback signal operates to modify the gain control signal to reduce an amount of variability in a VGA gain slope over a range of VGA output power.

Abstract: An arrangement for saving energy in a radio device transmitter and a radio device. The steady currents of the transmitter amplifiers are made dependent on the transmitting power for reducing the losses of the amplifiers. The VGA (400) comprises at least one main differential pair (Q41–Q42; Q43–Q44) for controlling the gain and a bias differential pair (Q47–Q48) for controlling said steady currents. These pairs are steered by the one and the same voltage (?V), in which case the output current (Ib1; Ib2) of the bias differential pair changes in the same way as the output current (io1; io2) of the main differential pair when the gain is readjusted. The output current of the bias differential pair is used as a bias current of the transmitter amplifiers, i.e. as a current that determines the steady currents of the amplifiers.

Abstract: A temperature compensated amplifier with variable gain and to a radio device having an amplifier according to it. The gain control and temperature compensation of a differential amplifier (210) are implemented by a control circuit (220), which has a balanced and differential output (V1, V2). The output voltage of the control circuit, or the control voltage, is arranged to be proportional to difference between two source currents (IGT1, IGT2), which difference can be varied on both sides of zero. The output of the control circuit is connected to the bases of the differential pair (Q1, Q2) of the variable gain amplifier, whereupon the ratio of the output current (iout) to the input current (iin) of the pair becomes dependent on the control voltage. This is arranged to be proportional to the absolute temperature, too. A temperature change then changes the control voltage the more the higher the control voltage is.

Abstract: An arrangement for saving energy in a radio device transmitter and a radio device. The steady currents of the transmitter amplifiers are made dependent on the transmitting power for reducing the losses of the amplifiers. The VGA (400) comprises at least one main differential pair (Q41-Q42; Q43-Q44) for controlling the gain and a bias differential pair (Q47-Q48) for controlling said steady currents. These pairs are steered by the one and the same voltage (&Dgr;V), in which case the output current (Ib1; Ib2) of the bias differential pair changes in the same way as the output current (io1; io2) of the main differential pair when the gain is readjusted. The output current of the bias differential pair is used as a bias current of the transmitter amplifiers, i.e. as a current that determines the steady currents of the amplifiers.

Abstract: The invention relates to a device for frequency conversion, comprising exactly one multi-band mixer (3) with means for transferring a signal (2) that is applied to the signal input of said multi-band mixer (3) from said signal's source frequency band to one out of a plurality of target frequency sub-bands at a time, yielding a transferred signal (4) at the signal output of said multi-band mixer (3), wherein said plurality of target frequency sub-bands defines at least a first and a second target frequency band, and a bank of switchable Variable Gain Amplifiers (VGAs) (5-1, 5-2) for amplifying said transferred signal (4), wherein for each of said target frequency bands, one switchable VGA (5-1, 5-2) is provided that is adapted to said target frequency band and is connected to the signal output of said multi-band mixer (3). The invention also relates to a method for frequency conversion.

Abstract: A temperature compensated amplifier with variable gain and to a radio device having an amplifier according to it. The gain control and temperature compensation of a differential amplifier (210) are implemented by a control circuit (220), which has a balanced and differential output (V1, V2). The output voltage of the control circuit, or the control voltage, is arranged to be proportional to difference between two source currents (IGT1, IGT2), which difference can be varied on both sides of zero. The output of the control circuit is connected to the bases of the differential pair (Q1, Q2) of the variable gain amplifier, whereupon the ratio of the output current (iout) to the input current (iin) of the pair becomes dependent on the control voltage. This is arranged to be proportional to the absolute temperature, too. A temperature change then changes the control voltage the more the higher the control voltage is.

Abstract: A method is disclosed for operating a radio frequency transmitter chain component, as is a radio frequency transmitter chain component that operates in accordance with the method. The method includes receiving an input signal to be mixed with a signal output from an oscillator, where the input signal is received through an operational amplifier. The method further includes applying an output of the operational amplifier to an input of a mixing circuit, rectifying the input signal to produce a rectified input signal and controlling a common-mode output voltage of the operational amplifier with the rectified input signal. This process varies the power consumption of the component in a manner that is proportional to a value of the input signal. A further step couples a mixer output signal to an input of a VGA. The component may include both the mixer and the VGA. In the preferred embodiment the input signal and the mixer output signal are differential signals.