Abstract: Embodiments of a calibration system for third order intermodulation distortion (IMD3) cancellation and a wireless apparatus are disclosed. In an embodiment, a calibration system for IMD3 cancellation includes a cancellation circuit for IMD3 cancellation between a first transmitter and a second transmitter, and a controller coupled to the cancellation circuit and configured to for each frequency channel of the first transmitter, perform a pre-conditional calibration of the cancellation circuit, after the pre-conditional calibration, determine a phase configuration for the cancellation circuit, and after the phase configuration for the cancellation circuit is determined, determine an attenuation configuration for the cancellation circuit.

Abstract: Various embodiments relate to a cancellation circuit configured to generate a cancellation signal, including: an attenuator configured to attenuate a transmitted signal from an aggressor transmitter based upon a first attenuation value; an I/Q demodulator configured to split an attenuated signal into in-phase (I) and quadrature signals (Q); a phase interpolator configured to apply a calibration phase shift and a calibration attenuation to the I signal and Q signal and to recombine the I and Q signals; an auxiliary balun coupled to an output of the phase interpolator; and an auxiliary power amplifier with an input connected to the auxiliary balun configured to generate the cancellation signal, wherein the output of the auxiliary power amplifier is connected to an output of a victim transmitter.