A Novel Two-Stage Broadband Doherty Power Amplifier for Wireless Applications

Khan, Muhammad Saad; Wang, Xueli; Ullah, Rahat; Ahmad, Ibrar; Shahzad, Sulman; Arain, Qasim Ali; Tunio, Muhammad Zahid

doi:10.1109/lmwc.2017.2775157

Cited by 17 publications

(11 citation statements)

References 9 publications

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“…The comparison between this work and recent broadband DPA designs has been summarized in Table . From the table, it can be observed that the proposed DPA achieves a wider bandwidth when compared to all the other cases, except, which exhibited unsatisfactory poor back‐off efficiency and saturated efficiency. Compared with Reference , the proposed DPA not only show a broader bandwidth, but also better back‐off efficiency.…”

Section: Simulation and Measurement Resultsmentioning

confidence: 94%

“…To effectively amplify the modulated signals with high PAPR over a large bandwidth, the bandwidth enhancement techniques for DPA are essential. Some approaches have been proposed to achieve high efficiency and broad bandwidth, such as using different output architectures, and controlling the output current or voltage ratio of main and auxiliary devices . In Reference , with λ /4 impedance transformer eliminated, the structure fulfills the impedance requirement at back‐off and saturation respectively by using two different output matching networks (OMNs).…”

Section: Introductionmentioning

confidence: 99%

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Broadband Doherty power amplifier with improved band‐pass auxiliary network

Zheng

Xie

Zhou

et al. 2019

Int J RF Microw Comput Aided Eng

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In this article, a Doherty power amplifier (DPA) with improved band‐pass auxiliary impedance inverter is proposed for broadband operation. As a wideband DPA solution, the output matching networks of main and auxiliary devices are designed to achieve proper impedance matching at back‐off and peak power by employing a two‐point matching technique without the λ/4 impedance transformer. It is found that the modified band‐pass network has broader bandwidth feature and is compact in form from the comparison with some different topologies of matching networks. So, it is more suitable to be the auxiliary transformer to achieve the broadband configuration of DPA. For validation purpose, a Doherty power amplifier based on two commercially available gallium nitride HEMT (Cree CGH 40010F) devices was designed, fabricated, and measured. Under the drive of continuous wave (CW) signal, the measurement results show that the DPA has a 6‐dB back‐off efficiency of 35% to 48% and a saturated efficiency of 44% to 64% within the frequency band from 1.50 GHz to 2.35 GHz, which is about 44% fractional bandwidth.

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Section: Simulation and Measurement Resultsmentioning

confidence: 94%

Section: Introductionmentioning

confidence: 99%

Broadband Doherty power amplifier with improved band‐pass auxiliary network

Zheng

Xie

Zhou

et al. 2019

Int J RF Microw Comput Aided Eng

View full text Add to dashboard Cite

show abstract

“…From (9), (11) and [32], for which V c = V dc in (9) and R opt = 2V dc /I peak for the class-B mode in [32]…”

Section: Asymmetric Dpa Without Continuum Mode Active Load Modulationmentioning

confidence: 99%

“…For the V dc in the class-B mode to achieve peak output voltage swing, R opt = 2V dc /I peak must be equal to the fundamental impedance seen by the PA. Based on (11) and (12), the γ h parameter is finally derived as…”

Section: Asymmetric Dpa Without Continuum Mode Active Load Modulationmentioning

confidence: 99%

Harmonic‐tuned continuum mode active load modulation output combiner for the design of broadband asymmetric Doherty power amplifiers

Naah

Shi

et al. 2019

IET Microwaves, Antennas & Propagation

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The conventional Doherty output combiner limits the bandwidth of operation in the asymmetric Doherty power amplifiers (DPAs). In this study, an output combiner that is designed using a harmonic‐tuned continuum mode active load modulation technique is proposed with the main target of extending the bandwidth of operation in the asymmetric DPAs. Through this methodology, design equations are derived and multiple harmonic impedance solutions are provided. This offers greater freedom for designing the output combiner of the asymmetric DPA which consists of the impedance inverting network and the impedance transforming network. Moreover, enhancements in the efficiencies at back‐off and saturation power levels are made possible. The efficacy of the design strategy is demonstrated by the realised broadband asymmetric DPA prototype working within the band of 1.4–2.45 GHz. The experimental results have shown 54.55% bandwidth of operation, accounting for about 0.95–12.55% increment in bandwidth as compared with some recently published DPAs in the literature. Substantially, drain efficiencies within 35.5–52% at 6 dB output power back‐off level and 47.5–64.2% at peaking power level are also recorded from the experiments. The maximum output power and gain are recorded at 43.52 dBm and 13.03 dB, respectively.

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“…Several techniques for adequately meeting the broadband and high back-off efficiency requirements in the Doherty power amplifier (DPA) are reported in the literature. Among these techniques are the bias modulation, envelope tracking [1], continuous mode [2] and many others [3][4][5][6][7][8]. Although the DPA's performance in [2] is encouraging, continuous mode analysis was not provided.…”

Section: Introductionmentioning

confidence: 99%

Impacts of continuous modes approach on the back-off efficiency of Doherty power amplifiers

Naah

Shi

et al. 2019

Journal of Electromagnetic Waves and Applications

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This paper analyses the impacts of the harmonic-tuned hybrid continuous modes (HTHCMs) approach on the back-off efficiency of Doherty power amplifiers (DPAs). Based on the HTHCMs strategy, formulations are derived for designing the impedance inverting network (IIN) and impedance transforming network (ITN) in the DPA. Via the proposed approach, multiple impedance solutions for realizing broadband DPAs with substantial output back-off efficiency recovery is made possible. The potentiality of the design method is demonstrated by the realized prototype working from 1.4 to 2.45 GHz. Test results have shown over 50% drain efficiency at 6 dB back-off power.

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A Novel Two-Stage Broadband Doherty Power Amplifier for Wireless Applications

Cited by 17 publications

References 9 publications

Broadband Doherty power amplifier with improved band‐pass auxiliary network

Broadband Doherty power amplifier with improved band‐pass auxiliary network

Harmonic‐tuned continuum mode active load modulation output combiner for the design of broadband asymmetric Doherty power amplifiers

Impacts of continuous modes approach on the back-off efficiency of Doherty power amplifiers

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