Image Overview
Radial Power Combines for Solid-State Power Amplifiers
Development of solid-state RF power amplifiers has reached the point where it is now common to replace vacuum-tube power devices with solid state amplifiers in the VHF, UHF and Microwave Frequency ranges. However, transistors generally cannot come close to matching the kilowatt levels that tube amplifiers can provide for many radar and communication systems. Fortunately, RF transistors are relatively inexpensive, so high levels of RF power can be realized by summing the outputs of a large number of solid-state amplifier stages.
This approach to high power amplification has some potential advantages over vacuum-tube designs, two of which are 1) failure tolerance (one transistor failure should not degrade performance appreciably) and 2) hot replacement (changing one module while all others are operating). A critical component in the assembly of solid state power amplifiers is the power combiner, because it must dissipate very little power internally and ensure that the extremely high power incident from multiple solid state amplifiers translates to the output port, rather than back into one or more of the input amplifiers.
File:
