The Boeing Company

Peter Y Cheung

Jennifer L Vollbrecht

Lauriston Chin Wah

David L Crampton

Kuang Yung Liu

A method and apparatus for reducing intermodulation distortion is disclosed. In one embodiment, the method comprises the steps of accepting a sampled input signal V(t) wherein the input signal V(t) comprises a plurality of peaks; determining n peaks V,V, . . . Vof the sampled input signal V(t) exceeding a clip value Vat times t, t, . . . t; and modifying the sampled input signal V(t) by weighting the n peaks V,V, . . . ,Vexceeding the clip value Vof the sampled input signal V(t) by a function b(t) wherein b(t) is either a hard limiting function or b(t)=f(a, a, . . . a;t&#x2212;t,t&#x2212;t, . . . t&#x2212;t), wherein a,a, . . . aare weight values corresponding to the n peaks V, V, . . . V, and f(t&#x2212;t,t&#x2212;t, . . . t&#x2212;t) is a smooth shaping function. Intermodulation performance is then selectively improved in selected sub-bands by notch filtering prior to application to the non-linearity.

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Chino Hills, CA, United States of America

Peter Y Cheung