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A parallel circuit differential class-E power amplifier using series capacitance


Class-E amplifiers are attractive for wireless handsets because of their high efficiency and simple implementation. However, it requires inductors in its output matching network that are inherently low Q components affecting efficiency and may require significantly large area in fully integrated implementation. In this paper a novel approach of implementing parallel circuit differential class-E amplifier is presented. Instead of using an inductor parallel to the transistor drain of each amplifier, a single capacitor at the single ended side of the balun provides the parallel inductance effect to the switching transistors. As a result, number of inductors required for circuit implementation is reduced which means reduced losses, less area and better tuning of reactance can be achieved. A test circuit is implemented in 0.13 μm CMOS process. Measurement results verify the validity of the concept. The Power Amplifier achieves 22 dBm output power at 2.4 GHz from a 2.5 V with an overall Power Added Efficiency of 38 %.

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Correspondence to Hashim Raza Khan.

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Khan, H.R., Fritzin, J., Alvandpour, A. et al. A parallel circuit differential class-E power amplifier using series capacitance. Analog Integr Circ Sig Process 75, 31–40 (2013).

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  • Power amplifier
  • Parallel circuit
  • Class-E
  • Lattice L–C balun