Deconvolution in non-minimum phase microwave instrumentation circuits

Transfer function model-based deconvolution offers many advantages over transform-based deconvolution. These advantages are most evident in high-frequency systems which are difficult to characterize by spectrum analyzer data or by pulse tests due to the difficulty in generating test signals with sufficient energy at high frequencies. However, transfer function model-based deconvolution techniques become unstable when applied to nonminimum phase systems. This instability problem is solved through a novel technique in which the unstable poles are reflected about the unit circuit to make them stable; the data are then run through the resulting deconvolver in the reverse direction. Using computer simulations it is shown that this technique solves the instability problem, and offers results equal to or better than transform-based deconvolution techniques. Application of the approach to a 5-GHz measurement system used by Lawrence Livermore National Laboratory has confirmed its use with actual data