An orthogonality-based deembedding technique for microstrip networks

This paper introduces a new orthogonality-based method of extracting scattering parameters (deembedding) from numerical current distributions on microstrip networks. All deembedding methods require sufficient length in the network feed lines that only a fundamental mode arrives at the discontinuity. In our new method, the length of feed lines used to excite a network with only a fundamental mode can be shortened compared with other methods. On that basis, this new method can be used to improve other deembedding methods. Estimates of end susceptance and end conductance of the open-end discontinuity are used for performance evaluation. End conductance computations are highly sensitive to errors in computed numerical reflection coefficients, making the accurate analysis of the open-end discontinuity a particularly challenging deembedding example. Results show that the orthogonality-based method is both stable and accurate. In the case of the open-end discontinuity, significant improvement in performance compared to other deembedding techniques can be achieved.