Generating solid-state RF RF energy — the silent revolution

Plasma beams generated by RF energy are also suitable for cutting metals. RF energy tool set from Macom

Numerous new markets are opening up for RF energy technology — overall it has what it takes for a sustained change in whole sectors of industry.

The idea of generating solid-state RF energy by very accurately controlled transistors and power amplifiers is not exactly new. In part developers have already been working on it for more than 15 years. Because power transistors are not only suitable for base stations. Right from the start it seemed realistic that they can be used to produce electromagnetic waves for industrial drying processes for example, or for microwave ovens. “RF energy” was the name given the new technology.

In the meantime both LDMOS and GaN transistors have reached a level of performance suiting them for use in RF energy technology. Despite optimizations for power transmission, they can still be fabricated on lines handling transistors destined for base stations. That makes them relatively low-cost in production. A decisive advantage of RF energy technology: input power and output power to the load can be measured by network analyzers; a power amplifier can be controlled. This is where RF energy far betters magnetrons, which cannot be regulated. The result: frequency and amplitude of the RF signals and thus the energy can be set with unprecedented accuracy, and matched to the process.

RF energy technology also stands out for a number of other sizeable advantages: transistors draw much less energy than magnetrons to generate RF power for instance, they populate much less space, and they are longer lived. Assuming that prices for transistors drop, engineers outlined wholly new scenarios in which RF energy takes the place of technologies used to date, and makes entire applications possible in the first place. RF energy could not only replace magnetrons — one of the last strongholds of old tube technology that semiconductors were not yet able to supplant — in microwave ovens and heating plant for industrial drying. Power transistors could also generate the plasma in plasma lamps, and revolutionize that part of light technology out of the reach of LEDs.

But they could also ignite the gas mixture in combustion engines, not just increasing the efficiency of these engines by a few percentage points but also significantly improving it. You might ask why solid-state RF energy has long awaited its breakthrough. As is so often the case when a new technology is still in its infancy, it is the cost — not only of the transistors. The whole surroundings must be right, an ecosystem form about the new technology, leading to systems that users can apply at low cost. That extends from the transistors and amplification, through the necessary controllers and components to set up control loops, to the electromechanical components playing an essential role in a system: connectors, cables and circuit boards must be developed for the purpose and work together. Plus, the measurement technology must be developed through to environments in which users can create their subsystems for various applications.

With the RFEA to market acceptance and growth

That is why the RF Energy Alliance (RFEA) was founded. It constitutes companies from all these sectors — from transistor manufacturers, through producers of electromechanical components, to makers of systems such as microwave ovens, lighting or combustion engines. The RFEA thus covers the entire delivery chain, and will primarily ensure that development is coordinated, that standards emerge, and all enterprises act in concert, reducing the development risk for the individual company. It not only wants to cut the costs of the single components, but enable users to obtain cost-effective subsystems. Because they develop equipment in which RF energy technology works in obscurity.

Their customers are only interested in equipment that runs reliably, consumes less energy than what went before, that it offers more functionality, and does not exceed a certain price threshold.