An Intrinsically Linear Wideband Polar Digital Power Amplifier

Hashemi, Mohsen; Shen, Yiyu; Mehrpoo, Mohammadreza; Alavi, Morteza S.; Vreede, L.C.N. de

doi:10.1109/jssc.2017.2737647

Cited by 35 publications

(28 citation statements)

References 25 publications

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“…Therefore, when the main (peak) DPA is fully on, it operates in class-E. As the number of switching transistors in the main (peak) DPA decreases (at PBO), the fundamental impedances become complex with positive reactances, and the second harmonic impedances become mostly negative reactances (capacitive), thus operating similar to a class-J PA [43]- [45]. For small ACW M (ACW P ) ( < 30), the voltage swing on drain of the main (peak) DPA is small, therefore operating similar to a current source with an almost linear behavior [17]. The C D change is rather small since all the devices in the output stage are in parallel all the time.…”

Section: Digitally-controlled Class-e Doherty Pamentioning

confidence: 99%

“…Wideband efficiency enhancement is achieved by using reactance-compensated parallel-circuit class-E along with wideband impedance inverter and a novel wideband Marchand balun-based Doherty power combiner, implemented using re-entrant coupled lines with independent 2 nd harmonic control. Nonlinear sizing, multiphase RF-clocking and overdrive-voltage control been recently successfully used to linearize single PAs with both on-chip [16], [17] and off-chip [18] matching networks in circuit level without using DPD.…”

Section: Introductionmentioning

confidence: 99%

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A Highly Linear Wideband Polar Class-E CMOS Digital Doherty Power Amplifier

Hashemi

Zhou²,

Shen

et al. 2019

IEEE Trans. Microwave Theory Techn.

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This paper presents the first application of a digital-intensive intrinsically linear digitally-controlled class-E technique in a Doherty configuration. By careful nonlinear segmentation and multiphase RF-clocking along with overdrive-voltage control and automatic duty-cycle correction, it is shown that even the nonlinearities related to Doherty operation can be fully handled by the underlying design such that digital predistorion DPD can be in principle omitted. The nonlinearity behaviour of the whole digital Doherty PA is analyzed and closed-form equations are given to predict the AM-AM and AM-PM curves. In addition, time/phase mismatch between the Peak and Main branches and the AM and PM signals are accurately compensated. In order to achieve maximum intrinsic linearity, two separate chips with the same architecture, but different design parameters, are fabricated as the Main and Peak amplifiers in 40nm bulk CMOS. To achieve a large RF bandwidth and high passive combiner efficiency, a differential low-loss, wideband Marchand balun-based Doherty power combiner, implemented using re-entrant coupled lines with independent 2 nd harmonic control is proposed, and together with the matching network is fabricated on a two-layer PCB. The measured peak / 6 dB power-back-off P OUT , drain efficiency / power-added efficiency at 2.4 GHz are 17.5 / 12.2 dBm, 57 / 52 % and 36 / 25 % with VDD Main / Peak = 0.6 / 0.7 V. Measured results without using DPD show-41 dBc ACPR and-36 dB EVM for a 16 MHz OFDM signal at 2.5GHz. By using DPD, the measured ACPR and EVM of a 16 / 32 MHz OFDM signals are-52 /-48 dBc and-50 /-48 dB respectively.

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Section: Digitally-controlled Class-e Doherty Pamentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

A Highly Linear Wideband Polar Class-E CMOS Digital Doherty Power Amplifier

Hashemi

Zhou²,

Shen

et al. 2019

IEEE Trans. Microwave Theory Techn.

Self Cite

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“…In this modulation approach, a "constant envelope" signal is fed to the PA and the amplitude variations are applied directly to its supply voltage. Thus the requirement on the linearity of the PA is greatly relaxed [115,27,89,43,52]. However, there are disadvantages with polar transmitters like the 2.1.…”

Section: Transmitter Architecturesmentioning

confidence: 99%

“…However, there are disadvantages with polar transmitters like the 2.1. Transmitter Architectures misalignment of the r and θ signals, when they are combined, that gives rise to non-linearity terms and spectral regrowth [52].…”

Section: Transmitter Architecturesmentioning

confidence: 99%

Studies on Selected Topics in Radio Frequency Digital-to-Analog Converters

Sadeghifar

2019

Linköping Studies in Science and Technology. Dissertations

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The network latency in fifth generation mobile technology (5G) will be around one millisecond which is much lower than in 4G technology. This significantly faster response time together with higher information capacity and ultra-reliable communication in 5G technology will pave the way for future innovations in a smart and connected society. This new 5G network should be built on a reasonable wireless infrastructure and 5G radio base stations that can be vastly deployed. That is, while the electrical specification of a radio base station in 5G should be met in order to have the network functioning, the size, weight and power consumption of the radio system should be optimized to be able to commercially deploy these radios in a huge network. Last but not least I would like to especially thank my soulmate and my love Hoda. Without all your help, your devotion and patience, I would not be able to complete this work. Therefore, I dedicate this work to you.

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“…Benefiting from the lower circuit complexity and lower power consumption of digital circuits, the trend in transmitter systems is moving into digital domain by utilizing digital modulator and switch-mode power amplifier (SMPA) [1,2,3,4,5,6]. Outphasing transmitter is an attractive structure to achieve all these objectives [2,3,4,5].…”

Section: Introductionmentioning

confidence: 99%

An anti-alias harmonic-reject phase modulation for digital outphasing transmitter

Wang

Xie

Wang

et al. 2018

IEICE Electron. Express

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This paper proposes a sufficient anti-alias and harmonic-reject phase modulation (PM) technique for digital outphasing transmitter. Instead of using complicated spectrum shaping modulation or power-hungry digitalto-analog (DAC) and high-order filters, the proposed less-complex modulation employs cross point estimation (CPE) algorithm to improve the adjacent channel leakage ratio (ACLR) performance and adopts harmonic rejection algorithm to achieve out-of-band (OOB) noise attenuation. When evaluated with a 10 dB peak-to-average power ratio (PAPR) 16 QAM orthogonal-frequency-division-multiplexing (OFDM) signal with a 30 MHz intermediate frequency (IF) carrier, the proposed modulation achieves an ACLR of −65 dBc, providing 17 dB improvement compared with −48 dBc for conventional modulation. Moreover, 56 dB and 57 dB extra attenuations for the 2rd and 3rd images are achieved, respectively.

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An Intrinsically Linear Wideband Polar Digital Power Amplifier

Cited by 35 publications

References 25 publications

A Highly Linear Wideband Polar Class-E CMOS Digital Doherty Power Amplifier

A Highly Linear Wideband Polar Class-E CMOS Digital Doherty Power Amplifier

Studies on Selected Topics in Radio Frequency Digital-to-Analog Converters

An anti-alias harmonic-reject phase modulation for digital outphasing transmitter

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