Patent ID: 7884596

Claim:
A self-balancing bridge, comprising: an RF signal input, RF IN ; first through fourth nodes; four impedances, including Z 1 , Z 2 , Z 3 and Z 4 ; at least one comparator having first and second inputs; first and second RF detectors, each having an input and an output, wherein said output of said first RF detector goes to said first input of said at least one comparator, and said output of said second RF detector goes to said second input of said at least one comparator; wherein said first node joins RF IN , Z 1 and Z 3 , said second node joins the unused end of Z 1 , Z 2 and said input of said second RF detector, said third node joins the unused end of Z 3 , Z 4 and said input of said first RF detector, and said fourth node connects Z 2 , Z 4 and ground; wherein one of said impedances is a tunable impedance and has a configuration selected from the group consisting of reactive only, series reactive and resistive, parallel resistive and reactive, switched reactive, and switched reactive and resistive and parallel and/or series; and wherein the output of said at least one comparator connects to each of said tunable impedances.