An imaging receiver includes a low noise amplifier (LNA) module to receive and amplify the radio-frequency (RF) input signal; one or more switches configured to selectively pass RF input to one or more of the power detector circuits; one or more power detector circuits coupled to the switches to generate output voltages proportional to associated powers at their input ports; one or more reference circuits to provide reference signals to the switches; and one or more integrator circuits to integrate the output voltages of the power detector circuits.