Solid state circuitry has been steadily replacing vacuum-tube technology since its invention in 1948. Beginning with the early transistor radio receiver, and continuing with the television receiver and the computer, solid state systems have become ubiquitous in our society. As solid state systems have evolved there are two inexorable trends in their development, increasing operating frequency and increasing power output. In fact, two vacuum tube dominated applications, high powered HF, VHF, and UHF transmitters for broadcasting, and high powered microwave amplifiers for satellite systems are now migrating to solid state systems in response to those trends.

The key advantages of solid state over vacuum tube can be found in the areas of:
• Linearity
• Amplifier positioning
• Energy costs
• Sparing costs
• Personal safety
• Reliability
• Maintenance
• Management and control

In our white paper ‘Total Cost of Ownership - A Comparison of SSPA and TWTA Amplifier Systems’ we provide a more detailed discussion of these points.