Envelope Modulator for 1.5W 10MHz LTE PA without AC Coupling Capacitor achieving 86.5% Peak Efficiency

Sung, Si-duk; Hong, Sheng; Bang, Jeongho; Paek, Ji-Seon; Lee, Seung−Chul; Cho, Thomas Byunghak; Cho, Gyu‐Hyeong

doi:10.1109/tpel.2016.2519243

Cited by 18 publications

(12 citation statements)

References 25 publications

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“…In [2][3][4][5], where the principles of SPA implementation are considered, the problem of envelope signal harmonic distortions caused by imperfect features of transistors (non-zero switching time, forward on voltage drop, influence of parasitic inductance of outputs of transistors and elements of the printed circuit board, etc.) isn't raised.…”

Section: Introductionmentioning

confidence: 99%

A time-reduced method for calculation distortions in envelope tracking power amplifiers

Pergushev¹,

Sorotsky²

2018

Instrumentation Engineering, Electronics and Telecommunications

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Pergushev A. O., Sorotsky V. A. "A time-reduced method for calculation distortions in envelope tracking power amplifiers" To increase the efficiency of power amplifiers in wireless telecommunications systems, whose signals have a high peak to average power ratio, the envelope tracking method can be used. This method involves forming of a low-frequency envelope signal by a switched-mode power amplifier (SPA), which is then used as a supply voltage for a RF power amplifier. A specific feature of the SPA is that its output signal has high level of harmonic distortions. To evaluate these harmonic distortions, computer simulation can be used. However, time required to perform one cycle of simulation can be as much as several hours because of high complexity of SPA models. To reduce the simulation time of signal spectrum, approximate method that allows to represent the output voltage of a SPA in analytical form can be used. However, in known publications, the non-zero switching time of transistors is not taken into consideration, which leads to an appreciable error in the determination of the spectral components. This paper presents a method of analytic calculation of SPA output signal spectrum that considers the linear and exponential approximations of non-zero switching times of transistor. It allows to decrease the error in determining the harmonic distortions from 30…35 dB to 1…6 dB and to reduce the time expenditure as compared with computer simulation as much as 300 through 800 times.

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Section: Introductionmentioning

confidence: 99%

A time-reduced method for calculation distortions in envelope tracking power amplifiers

Pergushev¹,

Sorotsky²

2018

Instrumentation Engineering, Electronics and Telecommunications

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“…compared to other approaches such as the CDA-only [58][59][60][61][62][63][64] and the Class AB amplifieronly [81] architectures. In view of this, the hybrid CDA is ubiquitous as the choice of supply modulator for ET PAs and it is the architecture of interest in our designs.…”

Section: Ab -mentioning

confidence: 99%

“…Many supply modulators in ET PAs employ a hybrid topology (switching-cumlinear) [65][66][67][68][69][70][71][72][73][74][75][76][77][78]. This is because the hybrid CDA features higher power-efficiency compared to the Class AB amplifier-only topology [81], higher bandwidth and lower output ripple compared to the CDA-only topology [58][59][60][61][62][63][64] voltage of the input signal is 1.8V and the AC amplitude is 1.4V pp . In the low frequency range (<5MHz), is much higher than , and both and remain largely unchanged.…”

Section: _ IIImentioning

confidence: 99%

“…5-8), the power-efficiency remains >80% for a wide range of output power, from 0.5W to 1.8W.Fig. 5-14(c)compares the dynamic efficiency of the proposed supply modulator against the state-of-the-art designs[60,61,68,69,74,75].The proposed supply modulator improves the dynamic power-efficiency broadly and is capable of supplying the maximum output power of 1.8W. Measured results of the (a) transient response of the supply modulator of tracking a 40MHz LTE envelope signal (b) power-efficiency of the supply modulator tracking the 40MHz LTE with various output power (c) its comparison with state-of-the-…”

mentioning

confidence: 95%

“…This is because the switching frequency of the CDA is required to be at least 5x wider than the bandwidth of the input signals to suppress the switching noise [11], and the ensuing high switching frequency results in significant large power loss [35]. Although some design techniques such as dual-switch [60], multi-phase [61], multi-level [62], have been proposed to reduce the required switching frequency of the CDA, the bandwidth of the state-of-the-art CDAs [58][59][60][61][62][63][64] is still relatively narrow (insufficient), which is limited to ~10MHz. In the contrast, the hybrid CDA comprising a wideband Class AB amplifier and a power-efficient CDA, depicted in Fig.…”

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confidence: 99%

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Analysis and design of switching amplifiers for smartphones

He¹

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The past years as a Ph.D. student have been a special journey for me with many fond memories. Without the kind assistance of many people, it would have been very difficult for me to achieve this work. First of all, I would like to express my gratitude to my advisor, Prof. Joseph Chang. Prof. Chang guided me throughout my entire Ph.D. program with his outstanding academic wisdom and valuable suggestions. His support throughout these years helped me to move forward. It was one of my most enjoyable experiences learning from his profound knowledge and expertise. I would like to thank my co-advisor, Dr. Yu Rongshan. He offered valuable guidance as well as kind support throughout this Ph.D. program. I am especially grateful to Dr. Ge Tong for discussions pertaining to the technical aspects in this research program.

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Dual-Mode Supply Modulator IC With an Adaptive Quiescent Current Controller for Its Linear Amplifier in LTE Mobile Power Amplifier

Shin

Choi

et al. 2021

IEEE Access

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This article presents a hybrid envelope tracking (ET) supply modulator (SM) integrated circuit (IC) based on a Class-AB linear amplifier (LA) with supply voltage and temperature insensitive quiescent current. For ET mode, to further improve efficiency of the ET-SM, the supply voltage of the LA can be modulated using an additional dc-dc converter according to the average output power. An adaptive quiescent current controller for the LA of the ET-SM is proposed to maintain its quiescent current for large variations in voltage and temperature. Due to the insensitive quiescent current over the voltage of the LA, the supply voltage to the LA can be controlled in a wider range for the average output power, which allows the power amplifier (PA) in the ET mode to have a greater improvement in efficiency. The size of the output stage of the LA is also discretely reconfigured using 3-bit digital control to reduce the power consumption of the LA according to the output power level. For the low average output power levels, the operation mode is changed to APT mode, which supplies a reduced dc voltage according to the reduced average output power to the PA. The proposed SM, dc/dc converter and PA ICs were designed and implemented using CMOS processes for 0.9 GHz LTE application. Using an LTE uplink signal with a signal bandwidth of 5 MHz and a PAPR of 7.5 dB, a PAE of 38.4% at an average output power of 24.0 dBm was obtained under an ACLR of -30.0 dBc for the overall ET-PA. At a 6 dB back-off for the average output power, a PAE of 24.6% was achieved using the ET mode. A maximum PAE improvement of 8.0% point using the proposed SM IC was achieved compared to the stand-alone PA.INDEX TERMS power amplifier integrated circuit, supply modulator, envelope tracking, average power tracking, dual-mode power amplifier.

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Envelope Modulator for 1.5W 10MHz LTE PA without AC Coupling Capacitor achieving 86.5% Peak Efficiency

Cited by 18 publications

References 25 publications

A time-reduced method for calculation distortions in envelope tracking power amplifiers

A time-reduced method for calculation distortions in envelope tracking power amplifiers

Analysis and design of switching amplifiers for smartphones

Dual-Mode Supply Modulator IC With an Adaptive Quiescent Current Controller for Its Linear Amplifier in LTE Mobile Power Amplifier

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