RF Cooking Ovens

Abstract

The generation of microwave energy by solid-state semiconductors has recently been acknowledged as viable, and perhaps preferable. The reason for this is that solid-state technology allows for the capability for control over electromagnetic properties and characteristics of the microwave system [1]. These properties include the phase, the amplitude, and the frequency. With this amount of control, it is expected, and even demonstrated, that the two main characteristics of microwave generation and delivery system (efficiency and heating uniformity) can be improved significantly. It is not enough, however, to simply control and manipulate the properties mentioned above; there must be a feedback system that would allow this to be done in an intentional manner. There is yet another important difference between magnetron and solid-state technology, namely the ability to measure and respond to forward and reflected power levels. A typical solid-state RF (SSRF) generation system is comprised of a small-signal generation section, a high-power amplifier connected to a heat sink, and a power supply to drive the respective electronics [2]. The feedback, which is typically built into the power amplifier, then allows for the monitoring of the frequency, the phase, and the power levels. With these parameters, and the ability to manipulate them, it is not difficult to imagine that algorithms could be developed that could control these properties in a way which is responsive to the load contained within the cavity.