The DC-RF Conversion Efficiency Change of Magnetron with Thermal Condition

Converters that change DC power to microwave power are applied in various industries. Such converters can be categorized as magnetrons, traveling wave tubes (TWTs), and semiconductor converters. The magnetron has merits of high power and small size. The magnetron, as depicted in figure 1, can be a high- power transmitter for a space satellite, since the magnetron is a low-cost device and that is in mass produced ground use (Mitani et al., 2004; and Kitagawa et al., 1989). The magnetron, however, has demerits of in poorly stabilized output frequency spectra and variations in efficiency. The purpose of this study is to investigate the DC-RF conversion efficiency change of magnetrons with thermal condition.