Design and performance of microstrip-to-slotline transition

This paper describes the work involved in designing a microstrip-to-slotline transition (S.B. Chon, IEEE Trans. Microwave Theory and Tech., vol. MTT-17, pp. 768-778, 1969; J.B. Knorr, ibid., vol. MTT-22, pp. 548-554, 1974). Two of these transitions would be required in order to meet the specifications for obtaining a maximum insertion loss (S₂₁) of -0.5 dB with a minimum return loss of -20 dB throughout the 8-10 GHz range. A CAD package for the design of RF/microwave circuits has been used to analyze and optimize the transition performance. Simple transmission line circuit models were used to optimize the design. The transition would be fabricated on 1.27 mm thick RT-Duroid 6010.2 substrate and the S-parameters would be measured using standard SMA connectors and an HP-8501A Network Analyzer. A spectral domain Galerkin´s method is used to compute the characteristic impedance of wide slotline on the substrate.