| 1. |
- Chani Cahuana, Jessica, 1988, et al.
(författare)
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Linearization of dual-input Doherty power amplifiers
- 2014
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Ingår i: International Workshop on Integrated Nonlinear Microwave and Millimetre-Wave Circuits, INMMiC 2014. ; , s. Art. no. 6815085-
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Konferensbidrag (refereegranskat)abstract
- This paper studies the linearity of dual-input Doherty power amplifiers. We propose a linearization scheme that uses a combination of an efficiency-optimized static splitter and a vector-switched digital predistorter. The performance of the proposed linearization scheme is evaluated on a dual-input Doherty power amplifier operating at 2.0 GHz with 42 dBm peak output power. Experimental results show that the proposed linearization scheme achieves a normalized mean square error of-43.7 dB and an adjacent channel power ratio of-55.8 dBc with a power added efficiency of 42.4%.
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| 2. |
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| 3. |
- Fager, Christian, 1974, et al.
(författare)
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Prediction of smart antenna transmitter characteristics using a new behavioral modeling approach
- 2014
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Ingår i: IEEE MTT-S International Microwave Symposium Digest. - 0149-645X.
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Konferensbidrag (refereegranskat)abstract
- A new technique for analysis of nonlinear effects in smart antenna array transmitter systems is presented. The analysis is founded on a new type of dual-input circuit behavioral model which allows nonlinear effects caused by antenna mutual-coupling and mismatch to be predicted under realistic wideband signal excitations. The model formulation enables direct interface with multi-port antenna S-parameters and detailed prediction of radiated field characteristics. The method is validated by over-the-air WCDMA measurements on a dual-antenna 2.14 GHz MIMO transmitter. The results demonstrate that antenna mutual coupling may lead to significant nonlinear distortion that cannot be compensated for by conventional linearization techniques.
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| 4. |
- Gustafsson, David, 1983, et al.
(författare)
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A GaN MMIC Modified Doherty PA With Large Bandwidth and Reconfigurable Efficiency
- 2014
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Ingår i: IEEE Transactions on Microwave Theory and Techniques. - : Institute of Electrical and Electronics Engineers (IEEE). - 0018-9480 .- 1557-9670. ; 62:12, s. 3006-3016
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Tidskriftsartikel (refereegranskat)abstract
- In this paper, we further develop the concept of a wideband Doherty power-amplifier topology with reconfigurable efficiency. This is done by presenting new theory that-in contrast to previous work-makes it possible to analyze how the performance of the amplifier depends on the input network properties and the choice of gate bias voltages. The utility of the presented theory is demonstrated by the design and characterization of a gallium-nitride monolithic-microwave integrated-circuit amplifier designed in close agreement with the theoretical findings. Continuous-wave (CW) measurements show that the fabricated amplifier provides more than 31% power-added efficiency (PAE) at 9-dB output power back-off over a 5.8-8.8-GHz frequency range, and that the efficiency can be reconfigured as predicted by the presented theory. Modulated measurements-employing digital pre-distortion (DPD) and a 20-MHz signal with 8.5-dB peak-to-average power ratio-show more than 32% average PAE across the same 5.8-8.8-GHz frequency range. Both the CW and the modulated measurements thereby verify the wideband performance predicted by the theory. In addition, modulated measurements at 7.0 GHz without DPD show that the amplifier can provide excellent raw linearity by demonstrating -41.0-dBc adjacent channel power ratio and -34.2-dB normalized mean square error.
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