Interference modulation for microwave dielectric heating
Microwave Field pattern synthesis using interference is proposed as a novel approach to microwave heating. It is based on ideas already well known from the optical bench (interference circles, holograms), but applied and adapted to microwaves. The angle of total transmission (Brewster's Angle) keeps reflections at the microwave to material interface to a minimum, thereby improving energy transfer. Signals from two injection-locked magnetron based sources are interfered with each other to demonstrate the idea. No direct limit is imposed on the number of sources by the topology. Simulation indicates that certain heating patterns can be obtained, simply changing relative phases between sources. Phase being variable, particular average heat distribution patterns can be realized throughout the interference space. Limits mainly occur as a result of material properties, especially loss, material dimensions and wavelength.