High-power solid-state microwave generator for rf energy applications
AssigneeCellencor, Inc.
InventorKenneth Kaplan
Life of this patent
Estimating the term…
Abstract
A microwave generating system includes a modular architecture which is configurable to provide power output from under 1-kilowatt to over 100-kilowatts. The various power levels are achieved by combining the RF outputs of multiple RF power amplifiers in a corporate structure. The system can be used on any ISM band. Each system component incorporates a dedicated embedded microcontroller for high performance real-time control response. The components are connected to a high speed digital data bus, and are commanded and supervised by a control program running on a host computer.
Claims20
A method of exciting of a gas plasma generator or similar device, comprising:
- a solid-state microwave generator producing a fast, high power microwave ignition pulse;
- and
- reducing power to a defined maintenance level;
- wherein a frequency and power level of the microwave ignition pulse and the maintenance level may be set by a user or may be automatically determined.
A solid-state microwave generating system used to excite and provide precise control of various types of gas plasma generator apparatus, wherein the microwave generator comprises:
- an exciter unit comprising a high-speed embedded microcontroller, a digitally controlled frequency synthesizer, an RF power amplifier, two wide dynamic range RF detectors receiving sampled forward and reflected power samples, a high speed, high dynamic range power control circuit, and a pulse width modulator circuit;
- wherein the microcontroller of the exciter unit executes algorithms capable of single frequency or selective frequency sweeping, output forward power, reflected power and return loss measurement, adaptive power control, output power measurement, and/or phase adjustment while the system is generating any RF power output level.
A method for tuning the generation of plasma with a high-power microwave system, the method comprising:
- automatically identifying and operating the high-power microwave system at an optimal frequency for an ignition pulse;
- igniting the plasma via the ignition pulse;
- and
- after the plasma has been initiated, determining the impedance level.
A system of exciting of a gas plasma generator or similar device using application of high speed pulsed or pulse width modulated microwave energy in order to provide enhanced control of the plasma, the frequency and duty cycle of the pulse mode is adjustable by the user, or automatically adjusted based on impedance measurement or readings from sensors incorporated into the plasma apparatus, where a microwave generator's exciter is keyed by a pulse width signal thus allowing very high speed pulse modulation.
A system of measuring return loss or load impedance by sweeping microwave energy across the band while measuring return loss or impedance, and in the process identifying the operating frequency or frequencies where the best impedance match occurs, and providing a two phase process to optimally tune the microwave generator to the plasma apparatus, wherein the first phase, a “Best Frequency” frequency sweep operation is performed to select the optimal frequency for the ignition pulse, and in the second phase, after the plasma has been initiated and the microwave power and the plasma generator impedance has changed significantly, the power is reduced to a level sufficient to maintain the plasma, and the system automatically determines the new frequency having the best impedance match by sweeping up and down in frequency in a bounded range to prevent an excess of reflected power that could cause the plasma to extinguish, while measuring the return loss or impedance of the plasma apparatus;
- and further wherein the optimum power and frequency settings for each phase can be stored for future use, so the tuning operation may not be required.
Dependencies are inferred from the claim text.