1. RF/microwave power Amplifiers are used in wireless communications, and also in applications such as jamming, imaging and RF heating.
2. Each application has its own unique requirements for power, frequency, bandwidth, load, efficiency, linearity, and cost.3. RF power is generated by a wide variety of techniques and devices.
4. An SSPA (Solid State Power Amplifier amplifies the input power into a larger of RF/microwave output power. There are a great variety of different PAs, and most employ techniques beyond simple linear amplification,
5. A transmitter contains one or more PAs, as well as ancillary circuits such as signal generators, frequency converters, modulators, signal processors, linearizers, and power supplies. The classic architecture employs progressively larger PAs to boost a low-level signal to the desired output power.
6. However, a wide variety of different architectures in essence disassemble and then reassemble the signal to permit amplification with higher efficiency and linearity
7. Almost every conceivable type of modulation is being used in one system or another. PAs and transmitters also find use in systems such as radar, RF heating, plasma generation, laser drivers, magnetic-resonance imaging, and miniature dc/dc converters.