Radar systems trade-offs vacuum electronics vs. solid state

During the first 50 years of radar, vacuum electronics devices (VEDs) were the major source of power for their final power amplifiers (FPA). While VEDs continue to be used in many current operational radars, solid-state transmitters are becoming a viable alternative in many applications due to their advantages in availability, maintainability, modularity, and, sometimes, performance. In most cases, a solid-state transmitter must be part of an integrated radar design process. Attempts to replace high-power vacuum tube transmitters in an existing radar, with footprint- and performance-equivalent solid-state versions, have proven difficult since VED based transmitters traditionally have been low duty cycle and solid-state transmitters need to be operated at a relatively high duty-cycle in order to be cost-competitive. This talk reviews system level pros and cons between vacuum tubes and solid-state devices for new radar systems. The important issues of cost, maintainability, and reliability, are application specific and thus difficult to address in general terms.