Patent ID: 7405382

Claim:
A microwave system, comprising: an electromagnet for providing a magnetic field; a magnetron having a cathode, an antenna, and an anode within and responsive to said magnetic field; a first transformer for providing a variable voltage, a second transformer having a primary winding responsive to said variable voltage and having a secondary winding split into a filament winding for providing a low AC signal to said cathode and a secondary winding for providing a high AC voltage a half-wave voltage doubler responsive to said high AC voltage for doubling and rectifying said high AC voltage and providing a pulsed DC signal; a ballast resistor, for maintaining nearly constant current and compensating for fluctuation in AC voltage in response to current increases, said ballast means being responsive to said pulsed DC signal and electrically dispose intermediate said half-wave voltage doubler and said magnetron anode for providing said pulsed DC signal to said magnetron anode where said magnetron is responsive to said magnetic field, pulsed DC signal, and AC signal provided to said cathode for emitting RF energy, wherein said ballast resistor connected between said half-wave voltage doubler and said magnetron anode; a microwave applicator, including a circular disc-shaped waveguide, having a top and a bottom, said circular waveguide being responsive to microwave signals from a microwave generator provided to said waveguide at an inlet at the outer edge of said circular waveguide for communicating said microwave signals through said waveguide; an inductive tuning post fixed in said circular waveguide, oriented parallel to the electric field to provide additional inductive susceptance in parallel with the waveguide; a depression on the top of said circular waveguide, and between said post and said inlet, said depression for receiving a sample.