The Full Form of EMTL is Electomagnetic Waves and Transmission Lines.

Electromagnetic waves are created by time‐varying currents and charges. Propagation of electromagnetic waves in space and in materials obeys Maxwell’s equations. Electromagnetic fields may be viewed as a combination of electric and magnetic fields. Stationary charges produce electric fields. Moving charges and currents produce magnetic fields. Maxwell’s equations describe how electric and magnetic fields are generated and altered by each other. Maxwell’s equations are a classical approximation to the more accurate and fundamental theory of quantum electrodynamics. Transmission lines are used to transfer electromagnetic energy from one point to another with minimum losses over a wideband of frequencies. There are three major types of transmission lines: transverse electromagnetic (TEM) mode, transverse electric (TE) mode and transverse magnetic (TM) mode. A quarter‐wave transformer is a matching network with bandwidth somewhat inversely proportional to the relative mismatch one is trying to match. Microstrip is a planar printed transmission line.