Research On Control Of High-power Microwave Source

The microwave plasma technology has an extremely broad range of applications, suchas plasma enhanced chemical vapor deposition, plasma surface treatment, and plasmaetching. Microwave source as the core of the microwave plasma device, its instability ofthe output power directly restricts the application and development of microwave plasmatechnology. Therefore, researching high-power and outputting high stabilize microwavesource is an important topic in the microwave plasma technology.The magnetron is the main power electronic devices for high-power microwave energy.Its properties are similar to high-frequency diode in orthogonal electromagnetic field space.In practical applications, due to the extremely harsh working conditions of the magnetron,if it can not perfectly control programs, subtle cathode voltage or anode currentfluctuations will cause a large change of the magnetron output power.Experimental results have shown that when the magnetron enters the normaloperating state. If the magnetron threshold voltage is constant, the cathode voltage can beapproximated as constant. Therefore, base on ATmega16L, this paper presents a controlscheme of microcontroller for magnetron anode current regulator. When providing a stableinput voltage to the magnetron, through magnetron anode current detection sampling,processing and incremental PI (Proportional-Integral) control algorithm to calculate thecontrol parameters, so as to effectively regulate the size of the field current value, andultimately achieve the purpose of microwave output power stability.CK-619high-power magnetron is used in this design, and its characteristics andworking principle are introduced. At the same time, this paper in-depth analyzes theadvantages and disadvantages of a variety of commonly used technical solutions, and thenproposes this control scheme. This paper also detail introduces of the method of thespecific hardware and software of the control program for each functional circuit portion,and debugging of the various parts. The analysis, design, verification and a series of work of the control program iscompleted. In order to reach the new high-power microwave stable output power, I believethat on this basis, through the continuous improvement of the system, a stable outputhigh-power microwave source will can be obtained.