A Zero-Voltage-Switching Contour-Based Outphasing Power Amplifier

Singhal, Nitesh; Zhang, Haoxing; Pamarti, Sudhakar

doi:10.1109/tmtt.2012.2190747

Cited by 13 publications

(11 citation statements)

References 33 publications

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“…1 with all input-port voltages V A -V D having the same magnitude V S , then one can solve (20) for the effective admittance Y eff,A -Y eff,D each of the PAs sees looking into the combiner as a function of the outphasing angles θ and φ (21) with all other PAs active. Note that the expressions in (21) are quite similar to the expressions derived for the effective admittances of the four-way combiner with base = λ/2 given by (7).…”

Section: Appendix Amentioning

confidence: 52%

Multi-Way Lossless Outphasing System Based on an All-Transmission-Line Combiner

Barton

Jurkov

Pednekar

et al. 2016

IEEE Trans. Microwave Theory Techn.

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Abstract-A lossless power combining network comprising cascaded transmission line segments in a tree structure is introduced for a multi-way outphasing architecture. This architecture addresses the suboptimal loading conditions in Chireix outphasing transmitters while offering a compact and microwavefriendly implementation compared to previous techniques. In the proposed system, four saturated power amplifiers interact through an all-transmission-line power combining network to produce nearly ideal resistive load modulation of the branch power amplifiers over a 10:1 range of output powers. This work focuses on the operation of the combining network, deriving analytical expressions for input-port admittance characteristics and an outphasing control strategy to modulate output power while minimizing reactive loading of the saturated branch amplifiers. A methodology for combiner design is given, along with a combiner design example for compact layout. An experimental four-way outphasing amplifier system operating at 2.14 GHz demonstrates the technique with greater than 60% drain efficiency for an output power range of 6.2 dB. The system demonstrates a W-CDMA modulated signal with a 9.15-dB peak to average power ratio (PAPR) with 54.5% average modulated efficiency at 41.1 dBm average output power.Index Terms-base stations, outphasing, power amplifier (PA), wideband code division multiple access (W-CDMA), Chireix, LINC, load modulation.

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Section: Appendix Amentioning

confidence: 52%

Multi-Way Lossless Outphasing System Based on an All-Transmission-Line Combiner

Barton

Jurkov

Pednekar

et al. 2016

IEEE Trans. Microwave Theory Techn.

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“…For high efficiency at power back-off nonisolating power combiners are used [9]. This results in loadpulling between the two branch amplifiers yielding the ZVS and ZSS conditions to be violated and consequently dropping the efficiency well below it's maximum (ideal) 100% [10].…”

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

“…In [10], variable duty cycle combined with variable drain capacitance and with a tunable load network were used to maintain ZVS and ZSS conditions in power back-off up to (ideally) 9dB back-off. The CMOS implementation of the technique, presented in [10], was employed in [11] at 1.85GHz. For higher than (ideally) 9dB back-off levels, the outphasing technique employed in [10], [11] resulted in a reduction of the efficiency due to non-zero switching losses (non-ZVS condition).…”

Section: Introductionmentioning

confidence: 99%

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Outphasing Class-E Power Amplifiers: From Theory to Back-Off Efficiency Improvement

Ghahremani

Annema

Nauta

2018

IEEE J. Solid-State Circuits

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Abstract-This paper presents an analysis of outphasing class-E Power Amplifiers (OEPAs), using load-pull analyses of single class-E PAs. This analysis is subsequently used to rotate and shift power contours and rotate the efficiency contours to improve the efficiency of OEPAs at deep power back-off, to improve the Output Power Dynamic Range (OPDR) and to reduce switch voltage stress. To validate the theory a 65nm CMOS prototype, using a pcb transmission-line based power combiner was implemented. The OEPA provides +20.1dBm output power from VDD=1.25V at 1.8GHz with more than 65% Drain Efficiency (DE) and 60% Power Added Efficiency (PAE). The presented technique enables more than 49dB OPDR and 37% DE and 22% PAE at 12dB back-off with reduced switch voltage stress.

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“…An overall linear response can be achieved using by combining the outputs of multiple of these nonlinear switching PAs. Chireix outphasing is an example of this technique, using a lossless, non-isolating power combining network such that the real part of the load seen by each PA depends on the relative (outphasing) angle of the PA inputs [1], [2]. A drawback of the Chireix technique is that the imaginary part of the PA loading also varies significantly with outphasing angle.…”

Section: Introductionmentioning

confidence: 99%

Four-way lossless outphasing and power combining with hybrid microstrip/discrete combiner for microwave power amplification

Barton

Dawson

Perreault

2013

2013 IEEE MTT-S International Microwave Symposium Digest (MTT)

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Abstract-This work demonstrates a four-way outphasing and power combining system for microwave power amplification using a novel power combining network. The ideally lossles combining network is implemented using a combination of microstrip transmission-line sections with discrete shunt elements. We present the derivation of the power combining network topology as well as practical implementation details.The new power combining network is demonstrated in a 50-W, 2.14-GHz power amplifier system using load modulation of switching GaN PAs through outphasing for output power control. The system has a peak CW drain efficiency of 59.5% and drain efficiency above 45% over a 8.17-dB outphasing output power range. In modulated tests with a signal bandwidth of 3.84 MHz, the system demonstrates 52% average drain efficiency for a 3.9-dB peak to average power ratio (PAPR) signal, and 38% drain efficiency for a W-CDMA signal with 9.6 PAPR.

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A Zero-Voltage-Switching Contour-Based Outphasing Power Amplifier

Cited by 13 publications

References 33 publications

Multi-Way Lossless Outphasing System Based on an All-Transmission-Line Combiner

Multi-Way Lossless Outphasing System Based on an All-Transmission-Line Combiner

Outphasing Class-E Power Amplifiers: From Theory to Back-Off Efficiency Improvement

Four-way lossless outphasing and power combining with hybrid microstrip/discrete combiner for microwave power amplification

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