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Shigeru WATANABE Shinji TAKATSUKA Kazutaka TAKAGI Hiromichi KURODA Yuji ODA
An effect of source harmonic tuning on linearity of power GaAs FET's under class AB operation is demonstrated. To improve efficiency of the power amplifiers, GaAs FET's are often poerated under class AB condition. Due to lower bias current, a class AB amplifier begins to show nonlinearity at lower input power comparing with class A operation, and as the power level of the input signal increases, however, an output power sometimes increases abruptly. From nonlinear circuit simulation, we have found this phenomenon is occurred by the distortion in gate RF voltage, and by suppressing even-order harmonics in the input circuit of GaAs FET, class AB amplifiers can be effectively linearized. In this paper, we show the condition for improving the linearity of power CaAs FET's under class AB operation by the source harmonic tuning technique.
Koji YAMANAKA Yasunori SUZUKI Shoichi NARAHASHI Takaya WADA Makoto KAWASHIMA Ken TAKEI Kazutaka TAKAGI Atsushi HONDA Zhengyi LI Liang ZHOU Yoji OHASHI Wataru HATTORI Yusuke TAKAHASHI
This invited paper is dedicated to introduce recent activities of Japanese microwave industries. 7 topics are introduced from major microwave companies in Japan. All topics are from invited talks in 2014 Asia-Pacific microwave conference (APMC2014) held in Sendai, November, 2014.