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UHF and X-Band Class-E amplifiers


Li, Shijie (1999) UHF and X-Band Class-E amplifiers. Dissertation (Ph.D.), California Institute of Technology. doi:10.7907/wrwt-7a21.


A Class-E amplifier consists of a single transistor which is driven as a switch and a passive output load network. The output load network is a tuned resonant circuit and is designed to minimize the voltage and current waveforms overlapping, thus minimize the power dissipation in the transistor. The Class-E amplifier is for high efficiency operation with a theoretical maximum efficiency of 100%, and in practice about 80%-90%. Design approaches for Class-E amplifiers are described. Designs and experimental results for one 440 MHz and two X-band Class-E amplifiers are presented in detail. The 440 MHz Class-E amplifier is implemented using lumped components and the active transistor is the Motorola MRF183 n-channel lateral MOSFET. It delivers an output power of 15 W, drain efficiency of 77%, power-added efficiency (PAE) of 70% with an input power of 1.4 W. For the two X-band Class-E amplifiers, one uses Fujitsu FHX35X HEMT as the active device and has an output power of 30 mW, drain efficiency of 80% and PAE of t 11.2 GHz. The other one uses Fujitsu FLR056XV MESFET and achieves an output power of 190 mW, drain efficiency of 72% and PAE of 56% at 9 GHz. The two X-band Class-E amplifiers are implemented using microstrip transmission lines.

Item Type:Thesis (Dissertation (Ph.D.))
Degree Grantor:California Institute of Technology
Division:Engineering and Applied Science
Major Option:Electrical Engineering
Thesis Availability:Public (worldwide access)
Research Advisor(s):
  • Rutledge, David B.
Thesis Committee:
  • Unknown, Unknown
Defense Date:24 July 1998
Record Number:CaltechETD:etd-02082008-163454
Persistent URL:
Default Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:565
Deposited By: Imported from ETD-db
Deposited On:20 Feb 2008
Last Modified:16 Apr 2021 22:15

Thesis Files

PDF (Li_s_1999.pdf) - Final Version
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