University of Oulu

B. Khan et al., "Simultaneous Measurement of Multiple Power Amplifiers for Phased Array Digital Predistortion Using a Shared Dual-Output Feedback," 2021 51st European Microwave Conference (EuMC), 2022, pp. 134-137, doi: 10.23919/EuMC50147.2022.9784203.

Simultaneous measurement of multiple power amplifiers for phased array digital predistortion using a shared dual-output feedback

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Author: Khan, Bilal1; Tervo, Nuutti1; Akbar, Rehman1;
Organizations: 1University of Oulu, Faculty of Information Technology and Electrical Engineering (ITEE)
Format: article
Version: accepted version
Access: open
Online Access: PDF Full Text (PDF, 0.9 MB)
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Language: English
Published: Institute of Electrical and Electronics Engineers, 2022
Publish Date: 2022-09-20


Digital linearization of a phased array transmitters is usually based on feedback measurements. Various arrangements can be used to measure multiple transmit paths by using conducted or radiated methods. We propose a technique for measuring any pair of transmit paths simultaneously by using a common feedback connected to two receivers, and a cancellation method that can make the measurements independent. Together with the feedback cancellation, a single feedback line with two output ports can be used to measure different transmit chain pairs coherently under varying load conditions present in phased arrays. The cancellation filters are trained by using a fifth-generation (5G) new radio waveform and verified by over-the-air (OTA) measurements along with the predistortion performance evaluation of a 28 GHz 8-element phased array transmitter. The method achieved 30 dB cancellation between the paths and the DPD trained with the feedback cancellation achieved 4.2 % EVM and -40.8 dBc ACPR.

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ISBN: 978-2-87487-063-7
ISBN Print: 978-1-6654-4721-8
Pages: 134 - 137
DOI: 10.23919/eumc50147.2022.9784203
Host publication: 2021 51st European microwave conference (EuMC)
Conference: European Microwave Conference
Type of Publication: A4 Article in conference proceedings
Field of Science: 213 Electronic, automation and communications engineering, electronics
Funding: This research work has been financially supported by Energy-Efficient Radio Access: Methods and Optimization (EERA) and Academy of Finland 6Genesis Flagship (grant no. 318927).
Academy of Finland Grant Number: 318927
Detailed Information: 318927 (Academy of Finland Funding decision)
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