A radio frequency, RF, receiver, comprising a receiver front-end (100, 600), the receiver front-end (100, 600) comprising: a passive mixer, having an input for receiving a radio frequency signal and an output for generating an output signal at a baseband: frequency or an intermediate frequency, wherein the input impedance and output impedance of the passive mixer are configured as high impedances so that the receiver front-end (100, 600) matches with a high impedance of baseband circuits and intermediate-frequency circuits, respectively; a gain control circuit, coupled between the output of the passive mixer and an input of an amplifier; and the amplifier, coupled to the gain control circuit; wherein the gain control circuit is arranged to detect a signal at the input of the amplifier to adjust a gain value that is exerted on the output signal generated at the output of the passive mixer to maintain linearity of the amplifier, characterized in that the gain control circuit comprises: a passive attenuation circuit, coupled between the output of the passive mixer and the input of the amplifier; and a detector, coupled to the passive attenuation circuit and the input of the amplifier, for sensing a level of the signal at the input of the amplifier, and sending a control signal to control the passive attenuation circuit to adjust the gain level to perform gain attenuation for a level of the output signal generated at the output of the passive mixer. a passive mixer, having an input for receiving a radio frequency signal and an output for generating an output signal at a baseband: frequency or an intermediate frequency, wherein the input impedance and output impedance of the passive mixer are configured as high impedances so that the receiver front-end (100, 600) matches with a high impedance of baseband circuits and intermediate-frequency circuits, respectively; a gain control circuit, coupled between the output of the passive mixer and an input of an amplifier; and the amplifier, coupled to the gain control circuit; wherein the gain control circuit is arranged to detect a signal at the input of the amplifier to adjust a gain value that is exerted on the output signal generated at the output of the passive mixer to maintain linearity of the amplifier, characterized in that the gain control circuit comprises: a passive attenuation circuit, coupled between the output of the passive mixer and the input of the amplifier; and a detector, coupled to the passive attenuation circuit and the input of the amplifier, for sensing a level of the signal at the input of the amplifier, and sending a control signal to control the passive attenuation circuit to adjust the gain level to perform gain attenuation for a level of the output signal generated at the output of the passive mixer. a passive attenuation circuit, coupled between the output of the passive mixer and the input of the amplifier; and a detector, coupled to the passive attenuation circuit and the input of the amplifier, for sensing a level of the signal at the input of the amplifier, and sending a control signal to control the passive attenuation circuit to adjust the gain level to perform gain attenuation for a level of the output signal generated at the output of the passive mixer.