Title :
Study on the robustness of a 22 MHz bandwidth feedforward amplifier at the 2.4 GHz ISM-band
Author :
Gilabert, Pere Ll ; Bertran, Eduard ; Montoro, Gabriel ; Berenguer, J.
Author_Institution :
Univ. Politecnica de Catalunya, Barcelona, Spain
Abstract :
Most wireless applications must accomplish stringent linearity normative specifications that prioritize parameters, such as adjacent channel power ratio (ACPR) or error vector magnitude (EVM), in front of power efficiency, the last being a quality parameter usually defined by the manufacturer. One possible solution capable of satisfying both requirements is the use of a linearizing structure for the power amplifier, the feedforward amplifier being one of the most suitable for wideband applications. The paper presents a study focused on the effects of disappointments on the delay paths and on the directional coupler factor in the feedforward structure. Therefore, a theoretical analysis on the tradeoff existing between the degradation on the ACPR and the improvement of the overall power added efficiency (PAE) is presented. The study has been carried out using a 22 MHz bandwidth π/4 DQPSK modulated signal.
Keywords :
UHF power amplifiers; delays; differential phase shift keying; digital radio; feedforward; linearisation techniques; mobile radio; quadrature phase shift keying; 2.4 GHz; 22 MHz; DQPSK modulated signal; ISM-band; adjacent channel power ratio; delay paths; digital mobile communications systems; directional coupler factor; error vector magnitude; feedforward amplifier; linearizing structure; power amplifier; power efficiency; wideband applications; Bandwidth; Broadband amplifiers; Degradation; Delay; Digital signal processing; Feedback; Frequency; Linearity; Power amplifiers; Robustness;
Conference_Titel :
Personal, Indoor and Mobile Radio Communications, 2004. PIMRC 2004. 15th IEEE International Symposium on
Print_ISBN :
0-7803-8523-3
DOI :
10.1109/PIMRC.2004.1370861
