The transmission-line high-efficiency class-E amplifier

High-efficiency switched-mode (heavily saturated) circuits such as the class-E amplifier are well-known in the MHz frequency range. Here, a microwave transmission-line class-E amplifier is presented. Design equations for the output circuit line lengths and impedances are derived, along with approximate equations predicting power and efficiency for the class-E amplifier. Microstrip circuits using the Siemens CLY5 MESFET demonstrate 80% power-added efficiency (PAE) at 0.5 GHz with 0.55 W of output power and 73% PAE at 1.0 GHz with 0.94 W. Experimental results compare favorably to a simplified design-oriented analysis.<
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