As has already been mentioned, an EMF standard with a segment of a transmission line, working in conditions of full matching in both its sides, has many advantages compared to sets radiating EM energy into space. The main advantages include a simple design, a possibility to generate quite strong EMF with relatively low exciting power, insensitivity to external fields and very limited energy radiated outside of a set, an ability to work in a wide frequency range, and simple and frequency-independent relationship between power (voltage) exciting a set and EMF inside it. The most important disadvantages include very limited space inside a set and strong couplings between a line and an OUT. The most popular and the most widely applied solution consists of a segment of strip line with basic mode TEM; this is usually called a TEM cell.