Microwave antenna for industrial use - uses individual waveguides coupled to principal guide quarter wavelength intervals and having dielectric inserts to shift phase

摘要

The antenna provides an electric field which is constant in amplitude and phase along its complete length and is used in drying, vulcanisation, polymerisation, and welding. The uniformly distributed field is obtained by juxtaposition of elementary fields set up in individual wave guides coupled to a principal supply guide operating in mode TE 10. Controlled lengths of low loss dielectric are placed in each individual guide to shift the phase of the waves by the required amount. Further phase control is obtained by tapering selected waveguides. To avoid internal reflections the take off guides are placed at quarter wavelength intervals along the principal guide.