V.A. Burobin, A.M.Konovalov, A.Y.Voloshin

System of broadband wireless access WiMAX is modern technology of data transmission of the fourth generation (4G). It provides high-speed and high-level access to the Internet and other multiservice services (an IP-telephony, video streams, and online games). There are high demands on the WiMAX electronic componental base, in particular, on characteristics of microwave transistors. Therefore, there is a need to develop a new type of transistors with improved characteristics. The microwave transistors, based on technology, using semi-conductor materials with wide band gap region, like gallium nitride (GaN), became such decision. The new generation of transistors has considerable advantages in comparison with the transistors made of silicon (Si) and arsenide of gallium (GaAs). Application of materials with the wide band gap makes it possible to use semiconductor devices based on them in extreme modes and conditions. The main feature of nitride structures - the formation of heterojunction AlGaN / GaN two-dimensional electron gas - it helps to increase power density and improve other specifications. On the basis of heterostructures AlGaN/GaN are made HEMT - high electron mobility transistors which possess such outstanding characteristics, as very high power density and a high-temperature mode. As shown in article, HEMT are the best option for use in WiMAX. Wide-gap semiconductors have unique properties that offer great possibilities of designing and manufacturing new types of microwave devices, in particular, for WiMAX. At the same time, some technological problems and constantly growing demands on the elemental basis require further development of new electronic components that meet the needs of modern technologies and protocols.