Microwave power module for atmospheric microwave-excited plasma contributable to the biomedicine

Abstract

In this thesis, microwave power modules for the plasma generation are proposed. The atmospheric pressure non-thermal plasma generated by proposed microwave module could be applicable to the biomedicine.Firstly, a board version of power module based on the design of microwave circuits is presented. For a goal of convenient environment with the plasma treatment, huge equipment is integrated on a board keeping the desirable functions. A 900 MHz λ/4 coaxial transmission line resonator (CTLR) is used to ignite Argon plasma with conditions of about 4 W and atmospheric pressure. Sterilization of S. mutans has been successful by the designed test board which results are followed.Secondly, a chip version of power module with resonant frequency tracking scheme is presented. This designed power module consists of a frequency synthesizer, power amplifier (PA), peak detector, flash ADC and digital control block of FSM. For the high-level integration, this module is implemented in a 0.35 μm BCDMOS process. The frequency synthesizer generates dual-band output such as 900 MHz and 1.8GHz. The normal output power of the PA with external load inductors and line patterns for the power matching is approximately 1 W. Helium plasma in a CTLR with metal tip has been ignited successfully by the designed test board on a heat sink (Aluminum) which is powered by a DC 15 V. The resonant frequency tracking scheme with a help of directional coupler having fixed attenuation constant adjusts repetitively the operating frequency after comparison of present and last reflected power at every period of loop clock.