EMF = Electromagnetic field and EMR = Electromagnetic radiation but what are they actually and how are they related?
Active terahertz waveguides based on transmission-line metamaterialsSPIE NewsroomCurrent research in this area investigates electromagnetic metamaterials for novel antenna concepts, sub-wavelength resonators and waveguides, superlenses that beat the diffraction limit, and even cloaking from electromagnetic radiation. Our research ……Active terahertz waveguides based on transmission-line metamaterials – SPIE Newsroom
Hopefully you understand EMF better. The links below give more insights about this topic.