RF energy is on the cusp of bringing changes to cooking, lighting, industrial heating, automotive spark plugs, and a host of other applications. It's made possible through the development of RF transistors that can provide sufficient power at the right frequencies, namely the 2.45 GHz ISM band. Yes, the same band used by Wi-Fi and Bluetooth.
As with any new technology, RF energy applications come with engineering challenges such as thermal dissipation, cost, size, and measurement. At EDICON 2016 in Boston, I met with Klaus Werner, Executive Director of the RF Energy Alliance, who also gave a presentation that day. After the conference, I spoke with Mark Murphy, Senior Director Marketing and Business Development for RF Power at MACOM and with Robin Wesson, Advanced Applications Architect at Ampleon.
"RF energy could change the way we cook food," said Werner, "but it's being used in other applications." He explained that RF energy, generated by RF transistors in power amplifiers, could replace the magnetrons in microwave ovens. By generating energy with semiconductors and more than one antenna (Figure 1), microwave ovens could produce energy sufficient for cooking and adapt to changing conditions as food cooks. That can result in more even cooking than we currently get from our microwave ovens, which essentially operate as on/off, open-loop systems. Instead, the next generation of microwave ovens will have complete closed-loop control. Some of today's ovens have mode-stirrers or turntables to attempt to produce a uniform field inside the cavity while others use humidity sensors that provide some feedback, but not enough, for the kind of control needed.