Research On Third-Order Harmonic Resonance Control Technology Of RF Power Supply

With the development of power electronic technology and semiconductor technology, the application area of RF power supply has been widely promoted. In order to overcome the disadvantages of high power electronic tubes RF power supply in large volume and low efficiency, and the disadvantage of solid-state RF powers in expensive RF powers transistors,a general MOSFET devices is used as the solid-state RF power device and full-bridge third-order harmonic resonance inverter topology is adopted, then the 2MHZ/2k W solid-state RF power is designed to meet the requirement of high power output and miniaturization. In this paper, the control mode of third-order harmonic resonance circuits is proposed to improve the switching speed and switching losses of general power MOSFET devices, so that it is suitable for higher operating frequencies. The main contents are as follows:Firstly, the solid-state RF power supply topology structure is introduced. The working principle of full-bridge series resonance solid-state RF power supply are briefly introduced in this paper, the working state and the series resonance component parameters design as well as the switching dead-time setting are analyzed. According to the topology of solid-state RF power supply, the control strategy of full-bridge third-order harmonic resonance was proposed to improve the working condition of the switch tube and the control principle of the third-order harmonic resonant circuit is analyzed.Secondly, the whole program and working principle of full-bridge third-order harmonic solid-state RF power is introduced, and the working principle of the solid-state RF power main circuit is analyzed and the components parameters are set. This paper presented in detail the design of main circuit topology structure and the important parameters; the auxiliary power circuit; the isolating drive circuit; the phase-locked loop control circuit and so on.Thirdly, the full-bridge solid-state RF power main circuit system is established and circuit parameters are set by using Or CAD PSpice simulation platforms. The simulation results in whether the access to third-order harmonic resonant circuit of RF power respectively is analyze.Then, the full-bridge third-order harmonic resonance solid-state RF power is tested for validation of the operation of the system, and the results of the phase-locked loop control circuit and the system are analyzed. The simulation results show that the full-bridge rf power with a third-order resonant circuit really improves the switching characteristics of the general MOSFET, the rising and falling time of the drain-to-source voltage is reduced from 44 ns to 22 ns, which is suitable for general MOSFET operate in higher frequency and reduces the switching loss of MOSFET, but the output power factor is reduced from 0.96 to 0.9.Finally, the characteristics of general MOSFET and RF MOSFET are compared in this paper. Then, electromagnetic interference and treatment measures of the RF power supply design and the RF power supply PCB layout are conclude.In this thesis, through the investigation of the 2MHz/2k W full-bridge third-order harmonic resonance solid-state RF power supply, the theory analysis, system simulation and hardware circuit design were completed.The thesis hopes to make a meaningful exploration on the development of high power solid-state RF power supply.