US Patent 7564305 System and method for self-cancellation of N

A method for reducing distortion in a nonlinear device whereby nth-order intermodulation products are canceled. A test signal is applied to the input of the nonlinear device and amplitudes of nth- and mth-order intermodulation products are measured. Transfer function coefficients and an optimum value of a baseband resistance are calculated. A baseband resistance is applied to an output of the device. An input signal is applied to the input of the device and a mth-order intermodulation product is passed through the baseband resistance and added back to the input. A system for practicing the same includes a signal source that generates the test signal, a unit that measures the intermodulation products, a unit that calculates the transfer function coefficients and the optimum value of a baseband resistance, and a unit that applies the baseband resistance to the output of the device.