Based on the equivalent circuit of the microstrip cross bend,the electromagnetic sensitivity model of discontinuous microstrip circuits with the presence of a uniform plane incident wave is established.First,the analytical expressions are modeled as equivalent voltage and current sources for discussing the global effect of the incident plane wave on the associated interconnects.Then,these field-induced equivalent source expressions are incorporated into ADS circuit solver,and a fast model is established for analyzing the output responses of microstrip circuits,such as the cross bend and the single-stage amplifier.The corresponding simulated results from the proposed model are also validated by comparing the results from the measurements.With the merit of short simulation time,the proposed approach would be an efficient method to solve the electromagnetic susceptibility problems associated with the discontinuous microstrip circuits.