Analysis of Envelope-Tracking Power Amplifier Using Mathematical Modeling

Kim, Jooseung; Kim, Dong–Su; Cho, Yunsung; Kang, Daehyun; Park, Byungjoon; Moon, Kibong; Kim, Bumman

doi:10.1109/tmtt.2014.2321356

Cited by 23 publications

(27 citation statements)

References 23 publications

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“…However, in the case of ignoring the output power level, the EER system has very low gain in lowpower regions due to the influence of the saturated operation of switching PA and the constant-envelope phase-modulated RF input signal [8]. Meanwhile, the envelope tracking (ET) PA, another popular efficiency enhancement technique, has been proposed in [8][9][10][11][12][13][14][15]. The technique modulates the supply voltage of the PA according to the input power level to reduce the dc power consumption at low power, but typically suffers from a complex system and a sophisticated supply modulator [10].…”

Section: Introductionmentioning

confidence: 99%

“…Meanwhile, the envelope tracking (ET) PA, another popular efficiency enhancement technique, has been proposed in [8][9][10][11][12][13][14][15]. The technique modulates the supply voltage of the PA according to the input power level to reduce the dc power consumption at low power, but typically suffers from a complex system and a sophisticated supply modulator [10]. In addition, both EER and ET still remain as important issues for the upcoming modulation schemes that tend to occupy wider bandwidths.…”

Section: Introductionmentioning

confidence: 99%

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A Low-Power CMOS Class-E Chireix RF Outphasing Power Amplifier for WLAN Applications

Zhu

2016

Wireless Pers Commun

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This paper describes the design and implementation of a low-power CMOS class-E Chireix RF outphasing power amplifier (PA) for WLAN applications. The proposed circuit is based on cascode class-E topology with two-stage structure and Chireix power combiner with a floating load. This class-E topology adopts self-biased technique and current-reused technique that avoids using thick-oxide transistors and can enhance the driving ability and power gain. Additionally, the Chireix combiner can reduce the loss of power and improve the efficiency by avoiding the use of isolation resistance. With a 2.5 V power supply, the realized prototype achieved 21.4 dBm of maximum output power and 29.9 % of average power-added efficiency (PAE) at 2.4 GHz. When operated for minimum input levels at 2.5 V, it reached 38.8 dB power gain. For a WLAN OFDM signal with 20 MHz, the error vector magnitude of 3 % is achieved with peak drain efficiency of 62 %. Moreover, the outphasing power amplifier is fully integrated with TSMC 0.18-lm CMOS technology and the chip area including testing pads is 1.07 9 1.17 mm 2 .

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

A Low-Power CMOS Class-E Chireix RF Outphasing Power Amplifier for WLAN Applications

Zhu

2016

Wireless Pers Commun

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“…The implementation of such new OFDM based schemes caused the new high-power transmitter designs to evolve during the past two decades. It is not only the demand for implementation of the new digital modulation schemes, but also the low efficiency of traditional linear amplifiers due to a high peak-to-average power ratio (PAPR) [3], which moves the traditional linear power stage transmitter construction to the high-power switching conception [4][5][6]. Nowadays, the pulse duration modulation (PDM) and its special case -pulse width modulation (PWM) -are the most common modulation techniques used in the new high-power AM transmitters [7], [8].…”

Section: Introductionmentioning

confidence: 99%

Analysis of Intermodulation Distortion in OFDM Based Transmitter Using EER Technique

Matejka

2016

RADIOENGINEERING

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“…Due to the power control strategy of wireless basestations according to the distance between the station and the user's equipment, the PA usually also operates at a back-off power level. However, the efficiency of the PA operated at the back-off power region is low and there are many studies about efficiency enhancement techniques at the back-off power region [1]- [12]. Among them, the envelope tracking (ET) PA is the most popular technique for a handset PA.…”

Section: Introductionmentioning

confidence: 99%

“…In recent research on the ET PA [12], the AM-AM and AM-PM of the ET PA are analyzed based on the inter-connection model between the PA and supply modulator. We have further investigated the distortion mechanism of an ET PA. For an ET PA with a sweep spot tracking, the AM-AM is very linear, but AM-PM is distorted.…”

Section: Introductionmentioning

confidence: 99%

Investigation of Intermodulation Distortion of Envelope Tracking Power Amplifier for Linearity Improvement

Moon

Cho

Kim

et al. 2015

IEEE Trans. Microwave Theory Techn.

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An intermodulation distortion of an envelope tracking (ET) power amplifier (PA) is investigated in this paper. For this purpose, the distortion characteristics are simulated based on the inter-connection model between the PA and supply modulator. For the sweet spot tracking ET operation, the fifth-order distortion is the most important one, which is generated by AM-PM nonlinearity. To reduce the distortion, the phase compensation network (PCN) is proposed. The efficiency of the PA is also improved by a properly designed bias circuit. For demonstration purposes, the PA and supply modulator are implemented using an InGaP/GaAs heterojunction bipolar transistor and a 0.18-m CMOS process, respectively. The ET PA is tested at 1.85 GHz using a long-term-evolution signal with 10-MHz bandwidth, a 7.5-dB peak-to-average power ratio, and 16 quadrature amplitude modulation. The ET PA with the proposed PCN and the bias circuit delivers a power-added efficiency of 44.3%, a gain of 23.4 dB, an evolved universal terrestrial radio access adjacent channel leakage ratio of 38.4 dBc, and an error vector magnitude of 1.8% at an average output power of 27 dBm. The multiband characteristics of the proposed ET PA are measured across 1.7-2.0 GHz. These results are achieved without any digitally supported techniques, indicating that the design approach is a promising technique for handset ET PA applications.Index Terms-Adjacent channel leakage ratio (ACLR), bias circuits, efficiency, envelope tracking (ET), intermodulation distortion (IMD), linearity, long-term evolution (LTE), phase compensation network (PCN), power amplifier (PA).

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Analysis of Envelope-Tracking Power Amplifier Using Mathematical Modeling

Cited by 23 publications

References 23 publications

A Low-Power CMOS Class-E Chireix RF Outphasing Power Amplifier for WLAN Applications

A Low-Power CMOS Class-E Chireix RF Outphasing Power Amplifier for WLAN Applications

Analysis of Intermodulation Distortion in OFDM Based Transmitter Using EER Technique

Investigation of Intermodulation Distortion of Envelope Tracking Power Amplifier for Linearity Improvement

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