Abstract: A controllable amplifier is disclosed. The amplifier includes two current paths which couple an input to an output of the controllable amplifier. Each current path has a respective transistor which is connected as source follower. One of the two current paths is designed to be controllable. It is thus possible to adjust the attenuation and hence the overall gain of the source/follower circuit as a function of a set value for the overall gain (CTRL). The circuit can be used as a variable gain amplifier (VGA), or as a programmable gain amplifier (PGA), in radio-frequency transmitters.

Abstract: A high frequency amplifier arrangement comprises a first stage with a modulator receiving a baseband signal, and a controllable current shunting device coupled with the modulator; a second stage coupled with the first stage comprising a gain controllable emitter follower; a third stage comprising a gain controllable amplifier coupled with the second stage; and a gain control unit for providing control signals for the first, second and third stage.

Abstract: A controllable amplifier and a method for amplifying a signal dependent on an analog control signal (CTRL) are disclosed. A first and a second amplifier transistor are each arranged with an assigned cascode transistor in respective current paths. The amplification value of the amplifier transistors in the different current paths is preset by means of a respective control signal by activation of the assigned cascode transistor dependent on a desired signal for the overall amplification (CTRL). The controllable amplifier has application to high-frequency transmission arrangements for signal amplification.

Abstract: A controllable amplifier is disclosed. The amplifier includes two current paths which couple an input to an output of the controllable amplifier. Each current path has a respective transistor which is connected as source follower. One of the two current paths is designed to be controllable. It is thus possible to adjust the attenuation and hence the overall gain of the source/follower circuit as a function of a set value for the overall gain (CTRL). The circuit can be used as a variable gain amplifier (VGA), or as a programmable gain amplifier (PGA), in radio-frequency transmitters.

Abstract: Method for controlling an output signal (A) of a voltage-current converting device, to which a reference voltage (UREF) is fed and in which a voltage signal (I, IX) applied on the input side is converted into a current signal, a reference voltage (UREF) setting the output quiescent current (I0). The provision of a setting device, which is connected to the reference input and is used to determine an envelope of an amplitude-modulated signal at the input is furthermore expedient.

Abstract: A high frequency amplifier arrangement comprises a first stage with a modulator receiving a baseband signal, and a controllable current shunting device coupled with the modulator; a second stage coupled with the first stage comprising a gain controllable emitter follower; a third stage comprising a gain controllable amplifier coupled with the second stage; and a gain control unit for providing control signals for the first, second and third stage.

Abstract: An amplifier arrangement includes a variable-gain signal amplifier. A control block is used to process a control signal in order to set the gain. A trimming unit acts on the control block such that signals which are produced by the control block can be trimmed relative to one another in order to set the gain of the signal amplifier.

Abstract: Method for controlling an output signal (A) of a voltage-current converting device, to which a reference voltage (UREF) is fed and in which a voltage signal (I, IX) applied on the input side is converted into a current signal, a reference voltage (UREF) setting the output quiescent current (I0). The provision of a setting device, which is connected to the reference input and is used to determine an envelope of an amplitude-modulated signal at the input is furthermore expedient.

Abstract: An amplifier arrangement includes a variable-gain signal amplifier. A control block is used to process a control signal in order to set the gain. A trimming unit acts on the control block such that signals which are produced by the control block can be trimmed relative to one another in order to set the gain of the signal amplifier.