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The purpose of this paper is to show how metamaterials with extreme values of permittivity and permeability, may be effectively used to design artificial magnetic conductors (AMC) at a given frequency. In particular, this paper theoretically determines, for the different polarizations of the incidence field, the conditions under which metamaterials can behave as an AMC.

In order to find out the required values of the constitutive parameters, this paper has done a theoretical analysis based on the transmission-line theory. The obtained analytical reflection coefficient has been particularized for the different possible polarizations of the incidence field in order to find the constitutive parameters values that this paper needs for the AMC behavior.

Depending on the polarization of the field, it is shown that different values of the constitutive parameters are needed to get AMCs. In particular, it is shown that in the case of TEM and TE polarizations, a large value of the permeability is enough to obtain an AMC boundary condition. In the case of the TM polarization, instead, the AMC boundary condition is effectively achieved by using a material with vanishing permittivity. The role of the permittivity in the three polarizations is discussed. Finally, possible implementations and applications at microwave and optical frequencies are presented.

The idea of using miniaturized inclusions to obtain AMCs is not completely new. However, to the authors' best knowledge, a complete and rigorous theoretical analysis showing the capabilities and the limits of this approach has not yet been presented in the open technical literature.

Challenge-based learning (CBL) has gained acceptance as a contemporary and progressive teaching pedagogy that provides a holistic and inclusive experience to learners in higher education (HE) institutions. However, its lack of appeal to non-STEM subjects and the need for further development, particularly concerning improved approaches, have been recognized. It seems that CBL runs the risk of becoming a portmanteau pedagogy that blends aspects of problem-based learning, project-based learning, and situated learning, as opposed to its development as an effective pedagogy tool. This points to a lack of a formal implementation framework, code of practice, and standard procedures for its delivery. We argue that blending a design thinking (DT) pedagogy with CBL can potentially provide the stability that CBL currently lacks. At the same time, it also presents a more inclusive proposition to potential non-STEM audiences. Thus, in this chapter, we seek to interrogate the intersectionality between CBL and DT literature in the context of HE teaching and learning with a view of establishing CBL as a pedagogy in its own right. We attempt to achieve this by systematically analyzing the separate literature to reveal the synergies and common touchpoints.