Method and an arrangement for compensating the temperature drift of a detector and a control signal in periodic control

The object of the invention is the compensation of the drift in a detector and a control signal (TXC), particularly in the control of the transmit power (RFOUT) of an RF time division TDMA signal (RFIN), for the control of which there is performed a power detection. According to the invention the voltage difference between the output voltage of the detection and the control signal is stored during a transmission pause, and during the transmission state the stored voltage difference is used to compensate the temperature drift of the detection and the control signal (TXC) in generating the gain control voltage (VCTRL). The voltage difference is stored in a capacitor connected between the detector and a feedback connected differential amplifier by connecting the inputs of the differential amplifier to each other and by connecting the output of the differential amplifier to a constant potential when the control signal (TXC) is connected to an input of the differential amplifier which is not that input to which said capacitor is connected. Also alternative ways to perform the storage are presented.