RF energy denotes a novel energy source making use of high frequency electromagnetic energy to power all kinds of applications in a VERY controlled way. This is in contrast to “ordinary” energy sources like infrared radiation or convection heaters or microwave ovens where the control of energy is LIMITED when compared to a RF Energy source.
A very familiar example of a currently available heating source is the domestic microwave oven that is often used to reheat food. In today’s appliances the RF energy is typically provided by a legacy microwave tube: the magnetron. The main limitation of the magnetron is it’s limited ability to adjust it’s output power especially in a changing environment.