Building solid state power amplifiers, microwave power modules and traveling wave tube amplifiers to operate in the Ka-band, Q-band, and other high-frequency bands is more challenging than operating at lower frequencies.

The Future of RF Amplification: TWTAs vs. SSPAs Revisited
The Future of RF Amplification: TWTAs vs. SSPAs Revisited By Mike Lee and Jose Gonzales, dB Control The short answer is: it depends on the application. First

