Advanced lumped-element filters for digital microwave power amplifiers
M. Martinez Mendoza1, A. Wentzel1, A. Alvarez Melcon2 and W. Heinrich1
Published in:
Int. J. Microwave Wireless Technolog., vol. 7, no. 5, pp. 589-596 (2015).
Abstract:
In this paper, two compact lumped-element band pass reconstruction filters for digital microwave power amplifiers applications in the 800 MHz band are presented. The filters, based on the trisection and quartet topologies, include cross-couplings which produce transmission zeros for maximum selectivity, and can be designed with practical element values. In contrast to common filter designs the input impedance characteristic is optimized broadband to values different from 50 Ω, as required for proper amplifier operation. Both filters achieve an insertion loss of around 0.8 dB and an equiripple bandwidth of 240 MHz (trisection) and 290 MHz (quartet), respectively, with improved out-of-band suppression. Results show that a considerable improvement in amplifier linearity and efficiency can be obtained with the new proposed filters, as compared with simpler filters traditionally used in power amplifier applications.
1 Ferdinand-Braun-Institut, Leibniz-Institut für Höchstfrequenztechnik, Gustav-Kirchhoff-Straße 4, 12489 Berlin, Germany
2 Technical University of Cartagena, Antiguo Cuartel de Antigones, Campus Muralla del Mar s/n, ES-30202 Cartagena, Murcia, Spain
Keywords:
Filters, Power amplifiers and linearizers.
© Cambridge University Press and the European Microwave Association 2015. Personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained from the Cambridge University Press and the European Microwave Association.
Full version in pdf-format.