Patent ID: 7071783

Claim:
A power sensing circuit for sensing radio frequency (RF) signals, comprising: a first transistor to perform as a detector diode, including i) a first base to receive a radio frequency input signal a DC bias signal from a regulated DC source coupled through a resistor, and a power-sensing signal; and ii) a first collector connected to the first base; b) a second transistor to amplify the DC component of the RF signal from the first base, including i) a second base connected to the first base through a low-pass filter; and ii) a second collector to output the power-sensing signal to be coupled to the regulated DC source through a resistor, said power-sensing signal being substantially proportional to the strength of the radio frequency input signal; and c) an output port coupled to the second collector through a low-pass filter, to output the power-sensing signal and a capacitor coupled to the first collector and the second base.