Analytical & experimental studies on impedance matching in RF generators for dielectric loads

Nowadays, high frequency waves have a so vital role in the industry. Cooking, pasteurization, defrosting, wood drying, etc. are some of the high frequency industrial applications. In this paper, an 800 W, 13.56 MHz radiofrequency heater has been designed, simulated and implemented. Variable loading is one of the major RF heaters problems. Usually, heaters have an optimum load in which they have their highest efficiency and the efficiency will dramatically decreased in heavier or lighter loading. Here, a type pi impedance matching system is used due to overcome this problem. Simulation results in Orcad software in two situations with and without impedance matching have been compared with laboratory results. These show that impedance matching system has greatly improved the amplifier´s efficiency.