Linear transmitter design using high efficiency Class E power amplifier

In this paper a linear transmitter design using high efficiency Class E GaAs power amplifier is presented. The advantages of this method over the existing methods of linearizing high efficiency saturated power amplifiers are discussed. The main building blocks in this technique: the Class E power stage and the phase correcting feedback are discussed in detail. Both an integrated version and a hybrid version of the Class E power stage operating at 835 MHz were designed and implemented in a self-aligned-gate, depletion mode GaAs MESFET process. The amplifiers deliver 24dBm of power to the load with a power added efficiency greater than 50% for the integrated version and 65% for the hybrid one. Issues related to the design of the limiting amplifier and phase shifter circuits used in the phase correcting feedback are presented.

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