Receiver with analog and digital gain control, and respective method

A method for operating a receiver comprising a first gain controlled amplifier, a mixer coupled with an input to an output of the first amplifier, a second gain controlled amplifier coupled with an input to an output of the mixer, a digital controller and a level detector, with the steps of

• receiving a plurality of communications channels with the first amplifier,
• selecting and downconverting a wanted communications channel by means of the mixer,
• evaluating the signal strength of the output signal of the second amplifier by means of the level detector,
• providing a digital gain setting for the second amplifier after selection of the wanted communications channel by means of the digital controller by changing stepwise the gain of the second amplifier until the output signal of the second amplifier is within a defined voltage range,
• freezing the digital gain setting when the output signal of the second amplifier is within said voltage range,
• enabling an analog gain setting for the first amplifier after freezing of the digital gain setting and demodulating the wanted communications channel,
• using the analog gain setting during demodulation of the wanted communications channel for keeping the output signal of the second amplifier within said defined voltage range, so that only the analog gain control and not the digital gain control is enabled during demodulation of the wanted communications channel.

A receiver comprising

• an RF input for receiving a plurality of communications channels,
• a first amplifier coupled to the RF input,
• a mixer coupled to the amplifier for downconverting a wanted communications channel,
• a second amplifier coupled with an input to an output of the mixer,
• a demodulator coupled with an input to an output of the second amplifier,
• an analog gain control for the first amplifier and a digital gain control for the second amplifier, and
• a digital controller providing a digital gain setting by means of the digital gain control after a selection of the wanted communications channel, freezing the digital gain setting and providing an analog gain setting by means of the analog gain control after said digital gain setting and during demodulation of the wanted communications channel
• wherein the control range of the digital gain control is at least 50 dB and the control range of the analog gain control is less than 20 dB.