Guest Editorial.

Moreover, they are particularly grateful to the authors of all the submitted papers for their efforts and contributions to this Special Issue, and to the reviewers for devoting their valuable time and expertise to review the submitted manuscripts. Authors of the accepted and presented papers during the iWEM 2021 were invited to submit expanded versions of their conference papers in this special issue. This special issue of Microwave and Optical Technology Letters (MOTL) includes nine expanded papers from the 2021 IEEE International Workshop on Electromagnetic: Applications and Student Innovation Competition (IEEE iWEM2021). [Extracted from the article]