This paper presents a novel approach to model device non-linearity using Tchebyshev Polynomials. Through rigorous analysis, the relationship between the IS-95 CDMA reverse link RF signal adjacent channel power regrowth (ACPR) and the two-tone intermodulation power spectrum density is established. This approach of CDMA ACPR prediction requires only the classical two tone measurement setup, and the data calculation is made by matrix multiplication. No CDMA signal source, vector network analyzer, or curve-fitting software is needed.