The derivation of equivalent formulae for asymmetric spurlines in microstrip medium

The equivalent formulae for the asymmetric spurline in microstrip line are proposed. The formulae are derived from circuit theory under the assumption of the equal mode phase velocity. Although the presented formulae are an approximation, the accuracy is excellent. In addition, these formulae are simpler than those published previously. To demonstrate the validity of our study, a two-stage spurline is designed and fabricated. The simulated and measured results are in very good agreement. © 2017 Wiley Periodicals, Inc. Microwave Opt Technol Lett 59:924–926, 2017