High-power linear-beam tubes

Traveling-wave tubes and klystrons have both demonstrated the capability of generating large amounts of microwave power, and today frequently compete for applications where high power is required. The choice between them is then based on a variety of parameters-this is illustrated by comparing typical modern tubes used in ground stations for satellite communication. The two technologies are increasingly being combined in a single amplifier, modern tubes with very high performance have resulted from this combination. One example is the extended-interaction klystron, which has generated the highest microwave power yet demonstrated, another example is the hybrid amplifier, which has demonstrated performance characteristics remarkably well-suited for modern radar systems. Performance has been extended upwards in frequency as well. Modern klystrons and traveling-wave tubes that generate high powers at millimeter wavelengths are described.