Broadside coupled striplines and suspended substrate microstrip lines for millimetre-wave applications

This paper presents, for the first time, design models of broadside coupled striplines and suspended substrate microstriplines which can be implemented on personal computers. The models have been obtained from the results of conformal transformation on homogeneous striplines, equivalence of the odd-mode with the quasi TEM mode of covered microstripline and logarithmic regression of spectral domain results. The present models represent at least an order of magnitude improvement in the computation time relative to the present numerical techniques. The design models presented will therefore be vital for fast and accurate computer aided design and optimization of microwave and millimeter-wave filters, couplers, DC blocks, mixers and various other useful circuits.