Microwave amplifiers are vital solid-state devices in the frequency range of 1to 100GHz to enhance the power, amplitude, or the oscillation span of input signals without providing additional distortion to its waveform, spectral composition and signal-to-noise ratio.
In other words, microwave amplifiers provide gain, stability, power, and linearity to the microwave signals received by it in a system.
Microwave amplifiers are used in all sorts of common electronic systems as also in ultra-tech electronic systems like electromagnetic compatibility systems (EMC), electromagnetic interference (EMI), defense systems, medical aid, and diagnostic systems, laboratory and field testing devices.
Microwave amplifiers are classified in many different ways. However, there are four broad categories based on the role it plays in generic super-heterodyne receiver.
Low noise amplifiers (LNA): Simple microwave amplifiers-takes low level signals from the transmission medium and amplifies it with minimal additional noise.
Power Amplifier (PA): Amplifies high level signals received and enhance it further to transmit it over lossy medium.
Linear signal amplifier (LSA): Generic amplifiers also called gain blocks. Provides signal gain with a system.
Driver amplifier (DA): Suited for single frequency operations as in synthesizers or amplifiers for local oscillator (LO) driving a mixer.
Microwave amplifier generates a lot of heat; hence need to ensure that it has a built-in cooling system, integral to its performance.