Zobrazeno 1 - 10
of 59
pro vyhledávání: '"Filipe M. Barradas"'
Publikováno v:
IEEE Journal of Microwaves, Vol 4, Iss 3, Pp 389-403 (2024)
This work originates from the realization that, in a transformed impedance thru-reflect-line (TRL) calibration, the sensitivity to random measurement errors is affected by impedance discrepancies between the impedance transformer and the device-under
Externí odkaz:
https://doaj.org/article/62af26f8e90947a8aa2da2ec10e49345
Publikováno v:
IEEE Access, Vol 12, Pp 41631-41642 (2024)
This paper analyzes the performance of the Doherty power amplifier (DPA) with the injection of the second harmonic component generated by the carrier power amplifier (PA) into the peaking PA and vice-versa, using a harmonic injection network (HIN). A
Externí odkaz:
https://doaj.org/article/cd5431efe74b4ddcb2855e60cb8cd75f
Autor:
Cristiano F. Goncalves, Filipe M. Barradas, Luis C. Nunes, Pedro M. Cabral, Jose Carlos Pedro
Publikováno v:
IEEE Access, Vol 9, Pp 38757-38766 (2021)
This paper presents a compact solution for impedance calculation obtained from low phase resolution stationary wave measurements, for RF power systems operating in load varying scenarios. The implemented system is based on a bi-directional coupler an
Externí odkaz:
https://doaj.org/article/d2574da3489d4051bf7b00ecb0ba7fd6
Publikováno v:
IEEE Access, Vol 7, Pp 152576-152584 (2019)
In Fifth Generation (5G) Multiple-Input Multiple-Output (MIMO) transceivers, Power Amplifiers (PAs) driving antenna arrays experience varying loading conditions. In fact, the input impedance of each antenna element changes within a Smith chart region
Externí odkaz:
https://doaj.org/article/80c7634b7e4b427a996b52f6021bc5d5
Publikováno v:
IEEE Access, Vol 7, Pp 172277-172289 (2019)
To fulfill 5th Generation (5G) communication capacity demands, the use of a large number of antennas has been widely investigated, and the array gain and spatial multiplexing that are offered by massive multiple input multiple output (mMIMO) have bee
Externí odkaz:
https://doaj.org/article/28cdfb0b11dd445c9a8aa912c1859282
Autor:
Filipe M. Barradas, Luis C. Nunes, Joao Louro, Diogo R. Barros, Pedro M. Cabral, Jose C. Pedro
Publikováno v:
IEEE Transactions on Microwave Theory and Techniques. :1-14
Autor:
Joao L. Gomes, Luis C. Nunes, Filipe M. Barradas, Adam Cooman, Aryan E. F. de Jong, Rob M. Heeres, Jose C. Pedro
Publikováno v:
IEEE Transactions on Microwave Theory and Techniques. 70:1377-1390
Publikováno v:
IEEE Transactions on Microwave Theory and Techniques. 70:779-789
This article presents a quasi-load insensitive (QLI) Doherty power amplifier (DPA). The proposed theory makes the amplifier load insensitive in terms of output power, while its efficiency is slightly degraded for complex loads. The load insensitivene
Publikováno v:
2022 17th European Microwave Integrated Circuits Conference (EuMIC).
Autor:
Pedro M. Cabral, Joao Louro, Jose C. Pedro, Luis C. Nunes, Catarina Belchior, Diogo R. Barros, Filipe M. Barradas
Publikováno v:
IEEE Transactions on Microwave Theory and Techniques. 69:2138-2147
This work presents a new artificial neural network (ANN) model formulation for RF high-power transistors which includes the S-parameters of the active device. This improves the small-signal extrapolation capability, and the OFF-state impedance approx