Microturbine also called a combustion turbine is a rotary engine that extracts energy from a flow of combustion gas. It has an upstream compressor coupled to a downstream turbine and a combustion chamber in-between. Energy is released when air is mixed with fuel and ignited in the combustor. The resulting gas is directed over the turbine's blades, spinning the turbine and powering the compressor and finally is passed through a nozzle, generating additional thrust by accelerating the hot exhaust gases by expansion back to atmospheric pressure. Energy is extracted in the form of shaft power, compressed air and thrust, in any combination and used to power aircraft, trains, ships, electrical generators and even tanks.

Microwave antennas are widely used in radar and communications applications. The basic principles of operation of microwave antennas are similar to those of antennas used at lower frequencies. These antennas are devices used to radiate electromagnetic energy into space. The characteristics of transmitting and receiving antennas are similar, so a good transmitting antenna is often a good receiving antenna.