Double pumped composite cavity 501 nm cyan laser with tunable injection power ratio

Introduction:This paper focuses on improving the power amplifier linearity for wireless communications. The use of a single branch of a power amplifier can produce high distortion with low efficiency.Method:In this paper, the Linear Amplification with Nonlinear Components (LINC) technique is used to improve the linearity and efficiency of the power amplifier. The LINC technique is based on converting the envelope modulation signal into two constant envelope phase-modulated baseband signals. After amplification and combining the resulting signals, the required linear output signal is obtained. To validate the proposed approach, LINC technique is used for linearizing an amplifier based on a GaAs MESFET (described by an artificial neural network Model).Conclusion:Good results have been achieved, and an improvement of about 40.80 dBc and 47.50 dBc respectively is obtained for the Δlower C/I and Δupper C/I at 5.25 GHz.

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Reduction of the peak to average power ratio (PAPR) for DVB systems using Gaussian based tone reservation and unused tones

China-Ireland International Conference on Information and Communications Technologies (CIICT 2007) ◽

10.1049/cp:20070768 ◽

2007 ◽

Author(s):

C. Devlin ◽

Anding Zhu ◽

T.J. Brazil

Keyword(s):

Average Power ◽

Power Ratio ◽

Tone Reservation

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Machine-Learning Assisted Optimisation of Free-Parameters of a Dual-Input Power Amplifier for Wideband Applications

Sensors ◽

10.3390/s21082831 ◽

2021 ◽

Vol 21 (8) ◽

pp. 2831

Author(s):

Teng Wang ◽

Wantao Li ◽

Roberto Quaglia ◽

Pere L. Gilabert

Keyword(s):

Power Amplifier ◽

Power Efficiency ◽

Average Power ◽

Long Term Evolution ◽

Input Power ◽

Global Optimisation ◽

Power Ratio ◽

Term Evolution ◽

Free Parameters

This paper presents an auto-tuning approach for dual-input power amplifiers using a combination of global optimisation search algorithms and adaptive linearisation in the optimisation of a multiple-input power amplifier. The objective is to exploit the extra degrees of freedom provided by dual-input topologies to enhance the power efficiency figures along wide signal bandwidths and high peak-to-average power ratio values, while being compliant with the linearity requirements. By using heuristic search global optimisation algorithms, such as the simulated annealing or the adaptive Lipschitz Optimisation, it is possible to find the best parameter configuration for PA biasing, signal calibration, and digital predistortion linearisation to help mitigating the inherent trade-off between linearity and power efficiency. Experimental results using a load-modulated balanced amplifier as device-under-test showed that after properly tuning the selected free-parameters it was possible to maximise the power efficiency when considering long-term evolution signals with different bandwidths. For example, a carrier aggregated a long-term evolution signal with up to 200 MHz instantaneous bandwidth and a peak-to-average power ratio greater than 10 dB, and was amplified with a mean output power around 33 dBm and 22.2% of mean power efficiency while meeting the in-band (error vector magnitude lower than 1%) and out-of-band (adjacent channel leakage ratio lower than −45 dBc) linearity requirements.

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Partial Power Processing Based Converter for Electric Vehicle Fast Charging Stations

Electronics ◽

10.3390/electronics10030260 ◽

2021 ◽

Vol 10 (3) ◽

pp. 260

Author(s):

Jon Anzola ◽

Iosu Aizpuru ◽

Asier Arruti

Keyword(s):

Electric Vehicle ◽

Power Converters ◽

Power Ratio ◽

Charging Station ◽

Fast Charging ◽

Full Power ◽

Processing Architectures ◽

Charging Stations ◽

Fast Charging Station ◽

Partial Power Processing

This paper focuses on the design of a charging unit for an electric vehicle fast charging station. With this purpose, in first place, different solutions that exist for fast charging stations are described through a brief introduction. Then, partial power processing architectures are introduced and proposed as attractive strategies to improve the performance of this type of applications. Furthermore, through a series of simulations, it is observed that partial power processing based converters obtain reduced processed power ratio and efficiency results compared to conventional full power converters. So, with the aim of verifying the conclusions obtained through the simulations, two downscaled prototypes are assembled and tested. Finally, it is concluded that, in case galvanic isolation is not required for the charging unit converter, partial power converters are smaller and more efficient alternatives than conventional full power converters.

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