Atsushi Takayanagi

Development of DC-DC converter for High/Low pulse voltage output using deadbeat control

Radio frequency (RF) pulse power generators are used for generating plasma in semiconductor product manufacture. Recently, the technology for manufacturing semiconductor products is developing rapidly. In proportion to this development, the RF generators are required to be able to generate a higher frequency High/Low (HL) pulse output with keeping an accuracy setting to a reference voltage. In addition, this generator is required to have a high responsive and the ability of the very wide range power output. The main circuit of the RF generator is a DC-DC buck converter. A 200 kHz switching prototype converter is built by using a proposed deadbeat control method. The responsive and stability of it is confirmed through a simulation and an experiment. The results proves that the experimental circuit can generate the stable 40 V/4 V high/low output with the output overshoot suppression. The rising time is less than 80 μs.

DC converter control using deadbeat control of high switching frequency for two-type operation modes

Recently, devices for manufacturing semiconductor products require plasma. Plasma is generated by two types of high frequency power, a High/Low and an ON/OFF output. A power supply, which can output the high frequency power is required to be more efficient and more compact. In order to achieve high frequency output with the High/Low pulse, the output capacitance in a power supply should be reduced. From this reduction, voltage vibration and voltage overshoot are increased. These problems can be solved by a suitable control, which keeps the output voltage stable. This paper proposes a deadbeat control which uses a reference current and replacement parameter of a load variation. The proposed method is capable of controlling output voltage without taking into account voltage vibration. The theory of the proposed method is evaluated by simulations. The availability of that is verified through experiments. The results obtained show that the proposed deadbeat control reduced the vibration range of the output voltage by half. In addition, the voltage overshoot is almost suppressed. The proposed deadbeat control realizes stable output of the ON/OFF pulse and enables high frequency output of the High/Low pulse.

A Wireless Power Transfer system optimized for high efficiency and high power applications

This paper summarizes the research progress in the field of Wireless Power Transmission (WPT) using Magnetic Resonance Coupling. To make the technique of WPT feasible for industrial and commercial applications it is vital to achieve a stable operation of power transmission from the source to the load under different conditions such as load and distance variations and antennas misalignment. To achieve a highly efficient transmission there are two parts that need to be improved. The AC/DC converter and the antenna system. We will show that a rectifier operating at 13.56 MHz with efficiency of 94% at power level of 1kW or more is feasible. On the other hand, the theoretical approach for optimizing the antenna system for optimum operation is derived along with its equivalent circuit and simulation. An overall efficiency of 89.11% at 1.5kW power and 12cm distance for the complete system from the RF source to the DC load was estimated by simulation and confirmed experimentally. A 3.7kW maximum power could be transferred in the experiment.

Analysis of impedance matching control

This paper is concerning a new impedance matching control used in the plasma processing. RF electricity is supplied to the plasma chamber and stability operation is required. For this purpose the impedance of the equivalent loads is controlled to be 50 [Ω]. Therefore the capacitance of capacitors in an LC circuit called a matching box is adjusted and the receiving end impedance is maintained to be 50 [Ω]. In this paper a novel control method of an impedance matching is proposed and the successful experimental results are presented.

Robust convergence of the impedance matching process based on seek control

This paper is concerning a new impedance matching method used in the plasma processing, and also for wireless power transmission. RF electricity is supplied to the plasma chamber and stabile operation is required. For this purpose the equivalent impedance of the loads is controlled to be 50 Ω. Therefore the capacitance of the capacitor in an LC circuit called a matching box is adjusted so that the receiving end impedance is maintained to be 50 Ω. In this paper a novel control method of an impedance matching is proposed and the successful experimental results are presented. A modification of the rate change of the matching elements improves the convergence time.