Starting with Chap. 6 , we begin utilizing full-wave methods for coupled EM simulations and the extraction of circuit models. In the first half of this chapter, we introduce fundamental concepts for analyzing field results obtained from EM simulations. We discuss the use of field probes and examine which simulation settings influence the accuracy of field calculations. Following this, we introduce field monitors and explain how to interpret the fields visualized by simulation tools. We then describe the methodology employed by simulation tools to obtain field values outside the computational domain. As an application example, we study the coupling of a signal from a twisted wire pair into an antenna. In the second part of this chapter, we introduce the basics of coupled simulations where the coupling path is represented using S-parameter models. We provide a detailed explanation of the circuit configurations in coupled models and describe how a tight coupling between the EM and circuit models enables the calculation of field distributions in the EM model, driven by source definitions at the circuit level. The advanced section of this chapter explores field monitors outside the computational domain and the use of field sources in EM simulations.