Title :
Design of a current mode class-D RF amplifier using load pull techniques
Author :
Schuberth, Christian ; Singerl, Peter ; Arthaber, Holger ; Gadringer, Michael ; Magerl, Gottfried
Author_Institution :
Inst. of Electr. Meas. & Circuit Design, Vienna Univ. of Technol., Vienna, Austria
Abstract :
This work presents the design of a current mode class-D (CMCD) amplifier using a measurement based approach. Because the CMCD amplifier is in fact a push-pull version of the inverted class-F amplifier the optimum load impedances for an inverted class-F single-ended operated LDMOS FETs have been determined using an active harmonic load-pull setup. The correct time domain waveforms for an inverted class-F amplifier were verified by measurements and simulations. Based on the harmonic load-pull measurements an experimental current mode class-D amplifier with 61.5% power-added efficiency (PAE) at 25W output is demonstrated using LDMOS FETs at 900 MHz.
Keywords :
MOSFET; UHF amplifiers; current-mode circuits; radiofrequency amplifiers; time-domain analysis; CMCD amplifier; LDMOS FET; RF amplifier; active harmonic load-pull technique; current mode class-D amplifier; efficiency 61.5 percent; frequency 900 MHz; inverted class-F amplifier; power 25 W; power-added efficiency; time domain waveform; Current measurement; Electric variables measurement; FETs; High power amplifiers; Microwave amplifiers; Power amplifiers; RLC circuits; Radiofrequency amplifiers; Switches; Voltage; Current mode class-D amplifier; LDMOS; high efficiency; microwave measurements; microwave power amplifiers; switching amplifiers;
Conference_Titel :
Microwave Symposium Digest, 2009. MTT '09. IEEE MTT-S International
Conference_Location :
Boston, MA
Print_ISBN :
978-1-4244-2803-8
Electronic_ISBN :
0149-645X
DOI :
10.1109/MWSYM.2009.5165998
