A receiver circuit that includes a direct conversion receiver that
receives a modulated signal, and generates an in-phase differential
signal and a quadrature-phase differential signal. The receiver circuit
includes an in-phase branch that processes the in-phase differential
signal, and a quadrature-phase branch that processes the quadrature-phase
differential signal. Each branch includes an amplifier and a summer. The
amplifier is configured to receive and amplify the respective in-phase or
quadrature-phase differential signal. The summer receives the resulting
amplified differential signal and sums the signals to generate a single
signal. A log amplifier receives the summed in-phase and quadrature-phase
signal, and generates an RSSI signal that is proportional to the log of
the difference between the two summed signals. The data may then be
extracted based on the amplitude of the RSSI signal.