Combination of Digital Second-Order Linearization Technique and DPD Compensation Technique - Concept and Results

Atanasković, Aleksandar; Budimir, D.; Males-Ilic, Natasa; Đorić, Aleksandra; Stosic, Biljana

doi:10.1109/icetran59631.2023.10192197

Cited by 3 publications

(5 citation statements)

References 7 publications

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“…Compared to the results attained in our previous research [5][6][7][8] it can be observed that the linearization achieved in simulation for QAM, OFDM, LTE and FBMC signals of the same bandwidth is of similar order depending on useful signal power level, i.e. when the power increases, the linearization effect of the applied technique deteriorates.…”

Section: Introductioncontrasting

confidence: 53%

“…The distorted DA output current (i out ) analyzed for the IM3 products is represented by (5) when approach-1 is used, and by (6) for the application of approach-2. Equations (7) and ( 8) encompass the IM5 products for linearization approaches, 1st and 2nd, respectively. The 1st and 2nd terms in ( 5) and ( 6) represent the DA linearity deterioration produced by the 3rd order nonlinearity of the DA carrier and peaking stages.…”

Section: Theoretical Background Of the Linearization Approachmentioning

confidence: 99%

“…The 1st and 2nd terms in (7) and ( 8) define the DA output current generated by the 5th order nonlinearity of the amplifier stages. The other terms of the 3rd order are the mixing products between the fundamental signals and the linearization signals from the first or the second approach and they can reduce the original IM5 products if their magnitudes as well as phases are correlated properly, [5], [8].…”

Section: Theoretical Background Of the Linearization Approachmentioning

confidence: 99%

“…A variety of techniques for amplifier linearization such as feedforward, feedback, predistortion [3] and different approaches of digital predistortion [3], [4] can be found in the literature. The authors of this paper anteriorly developed the digital linearization approach (DEB_LIN) [5][6][7][8] that uses the 2nd order digital signals adequately processed in magnitude and phase angles in the baseband, which then modulate the 2nd harmonic of the fundamental carrier. The generated linearization signals are injected at the gate and drain (input and output) of the PA transistor.…”

Section: Introductionmentioning

confidence: 99%

“…The results of the linearization obtained by this linearization approach in the simulation were already published for the single stage PA [5], [6] and the two-way DA [8], and tested for QAM, WCDMA, OFDM and LTE modulation schemes. Also, the linearization results were published for the single stage PA that operates in frequency around 3.5 GHz for UFMC, FBMC, and FOFDM modulation schemes with 50 MHz useful signal bandwidth [7]. The DEB_LIN approach was validated in experiments using the asymmetrical two-way microstrip Doherty amplifier for both the 16QAM signal with a 1 MHz frequency bandwidth and the 64QAM signal with a 2 MHz frequency bandwidth [6], [8].…”

Section: Introductionmentioning

confidence: 99%

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Linearization of the Fifth Generation Power Amplifiers by Injection of the Second Order Digitally Processed Signals

Atanaskovic,

Djoric,

Males Ilic

et al. 2024

RADIOENGINEERING

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This paper conducts a validation of two linearization approaches that utilize baseband nonlinear linearization signals of the 2nd order, through practical experiments on an asymmetrical two-way microstrip Doherty amplifier (ADA), and simulations on a symmetrical twoway Doherty amplifier (DA) as well as the single stage power amplifier (PA) for the post-OFDM 5G modulation formats. In the first approach, linearization signals are led at the input and output of the carrier transistor in the DA, while in the second approach, they are injected at the outputs of both the carrier and peaking amplifiers. The DA was tested in simulation for the FBMC signal of 20 MHz bandwidth, while the experimental measurements were performed for the FBMC signal on the ADA for different useful signal frequency bandwidths, 5 MHz, 7.5 MHz, and 10 MHz. The maximal improvement of DA linearity obtained in simulation is 10 dB for lower power and 5 dB for maximum amplifier output power, while the second approach gives around 2 dB better results for higher power levels. The experimental test for ADA performed for considered signal bandwidths indicates 3 dB to 5 dB linearity improvement for the implemented approaches and more symmetrical results achieved by the second approach. Additionally, the simulation tests for the PA were carried out for the FBMC, UFMC, and FOFDM signals of 100 MHz bandwidth, with the application of the first linearization approach. The minimal achieved linearization improvement is 13 dB for the FOFDM signal and a maximal of 18 dB for the FBMC signal.

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Section: Introductioncontrasting

confidence: 53%

Section: Theoretical Background Of the Linearization Approachmentioning

confidence: 99%

Section: Theoretical Background Of the Linearization Approachmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Linearization of the Fifth Generation Power Amplifiers by Injection of the Second Order Digitally Processed Signals

Atanaskovic,

Djoric,

Males Ilic

et al. 2024

RADIOENGINEERING

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Doherty Amplifier Linearity Test for Fifth Generation Signals

Atanasković,

Ilić,

Stošić

et al. 2023

2023 31st Telecommunications Forum (TELFOR)

Self Cite

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In this paper, the linearity of a fabricated microstrip Doherty amplifier in asymmetrical topology (ADA) is experimentally tested for the fifth generation signals. The measurement set-up contains a Matlab programming platform, a signal generator, and a vector signal analyzer. The Matlab development platform and the signal generator are used for the generation of the 5G FBMC, UFMC, and FOFDM signals. The 5G signal spectra are measured by the vector signal analyzer at the input and output of the Doherty amplifier. The output spectra of the 5G signals for different input power levels gained in measurements are compared to the simulated results.

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