Transistors made of silicon carbide, as developed in a research collaboration of Siemens and Russian scientists, manage to concentrate five kilowatts of power on a surface of just six square millimeters – a similarly powerful electron tube would require a volume of approximately ten liters. The advantage of silicon carbide is that the electrons can move in the material much more freely than in silicon. This allows ten-fold higher frequencies in the microwave range. They also dissipate the heat better and therefore can absorb more power. Siemens is one of the pioneers of silicon carbide technology and is now introducing it into corresponding applications.