Hier finden Sie wissenschaftliche Publikationen aus den Fraunhofer-Instituten.

Comparison of class A and class D RF amplifier operation with focus on reverse intermodulation and efficiency performance

: Kamper, M.; Ulbricht, G.; Weigel, R.; Fischer, G.

6th European Microwave Integrated Circuits Conference, EuMIC 2011. Proceedings : European Microwave Week, 10-11 October 2011, Manchester, UK
Manchester, 2011
ISBN: 978-2-87487-023-1
European Microwave Integrated Circuits Conference (EuMIC) <6, 2011, Manchester>
European Microwave Week <2011, Manchester>
Conference Paper
Fraunhofer IIS ()

A Current Mode Class D (CMCD) power amplifier at 900 MHz is presented. After a theoretical analysis, a class D amplifier is designed, simulated and afterwards assembled and characterized. Thereby, a maximum drain efficiency of 80.6%, and a maximum power added efficiency (PAE) of 72.8% at a switching frequency of 864 MHz, and an output power of 28.2 dBm were obtained. A linear class A amplifier using the same transistor exhibits a drain efficiency of 48.9% and 48.0% PAE at a comparable output power. An analysis of the reverse intermodulation distortion (IMD) of the switched-mode class D amplifier in comparison to the class A amplifier shows a 15dB improvement of the third order intermodulation ratio. To the authors' knowledge, this is the first practical verification of the superior reverse intermodulation performance of switched-mode amplifiers.