An error control method for application of the discrete cosine transform to extraction of substrate parasitics in ICs

This paper presents an error control method for application of the discrete cosine transform (DCT) to extraction of substrate parasitics in integrated circuits. In addition to the truncation error with approximating an infinite series with a finite number of terms, there are also errors in approximating the truncated series by the DCT. It is shown that this error is important for accurate parasitic extraction and isolation calculation and can be controlled by applying an interpolation method. The interpolation method also makes it possible to use a smaller DCT size without loss of accuracy.