High frequency noise reduction method of the class E power amplifier

Low-temperature dryers using the radio frequency (RF) electric field utilize dielectric heating to overcome disadvantages of conventional heat type dryer like shrinkage and damage of fabric. In order to increase the drying effect, a high frequency RF electric field of 13.56MHz is generated in the kW level. In several kW power circuits, 13.56 MHz is a relatively high frequency, resulting in a lot of noise. A method of reducing high-frequency noise by using harvesting in a low-temperature dryer is proposed. It utilizes the harvesting energy generated in the dryer; the magnetic energy of the motor and thermal energy of the drying unit. For verification of the proposed methods, the multi-channel power amplifier was connected to the real dryer load and used in the experiment.