Augmented behavioral characterization for modeling the nonlinear response of power amplifiers

Asbeck, P.M.; Kobayashi, Haruo; Iwamoto, M.; Hanington, G.; Nam, Sangwook; Larson, L.E.

doi:10.1109/mwsym.2002.1011577

Cited by 32 publications

(9 citation statements)

References 7 publications

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“…The drain voltage was swept from 1.5 to 6 V for ET design resulting in a three terminal nonlinear model. In case (2), the bare transistor model was converted into a load-dependent XP model, and the circuitry for bias and matching are embedded around the XP transistor model. The input power range and loads used for the XP extraction of the bare transistor are different from that of the whole PA.…”

Section: Simulation-based Xp Modelingmentioning

confidence: 99%

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Simulation and measurement-based X-parameter models for power amplifiers with envelope tracking

Jang

Zai

Reveyrand

et al. 2013

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

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-Static X-parameter (XP) models for RF power amplifiers (PAs), derived from both simulations and nonlinear vector network analyzer (NVNA) measurements, are investigated for the prediction of PA performance under dynamic signal conditions such as in envelope tracking (ET). The instantaneous AM-AM, AM-PM and PAE predictions of XP models extracted from simulation are compared under ET dynamic signal conditions to two types of circuit models using envelope simulation. An XP PA model is extracted for a peak 8W GaN class-F -1 ET PA from NVNA measurements with automated bias control. By applying a constant gain shaping table derived from the XP model to the drain supply voltage, the average PAE is improved from 40% to 57% for 3.84 MHz WCDMA signals at 2.14 GHz compared to fixed drain bias operation.

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Section: Simulation-based Xp Modelingmentioning

confidence: 99%

“…Nonlinear characterization and modeling of the transistor that can predict PA performance under varying bias and load is needed for more complex transmitters, such as those that employ envelope tracking [2]. A simplified ET block diagram is shown in Fig.…”

Section: Introductionmentioning

confidence: 99%

Simulation and measurement-based X-parameter models for power amplifiers with envelope tracking

Jang

Zai

Reveyrand

et al. 2013

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

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“…The overall input-output response of the system is given by Besides these linear memory effects, there are also some memory effects tightly coupled within the nonlinear circuits [28][29][30][31]. For example, thermal memory effects are caused by electro-thermal couplings.…”

Section: Memory Nonlinear Modelsmentioning

confidence: 99%

Adaptive digital baseband predistortion

Qian¹,

Zhou²

2011

Digital Front-End in Wireless Communications and Broadcasting

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The radio frequency (RF) power amplifier (PA) is the most power consuming element in a wireless transmission system, and can account for more than 50 percent of the total power consumed by the transmitter [1]. Improving the PA efficiency saves energy and drives down the overall system costs. A study described in [2, p. 13] provides a compelling reason for PA linearization: application of PA linearization technologies can yield annual savings of millions of dollars for a typical network service provider.Efficient PAs are usually nonlinear. Nonlinearity generates both in-band distortion and out-of-band interference, which manifest in terms of transmitter error vector magnitude (EVM) degradation and spectral regrowth. In wireless communication systems, many signal formats, such as Code Division Multiple Access (CDMA) and Orthogonal Frequency Division Multiplexing (OFDM) transmission, have been introduced to improve spectrum efficiency and data rate. However, these non-constant-envelope signals are not power efficient in the presence of nonlinear PAs as large back-offs are needed for linear transmission. In most commercial wireless communication systems, PAs are still the dominant source of signal quality degradation since the PAs are usually biased in a mildly nonlinear region to gain a reasonable amount of efficiency.Power amplifier linearization techniques can be sought to improve the linearity of the PA while still achieving a certain degree of power efficiency. Ideally, after linearization, the linear region of the PA is extended close to the saturation point of the PA, allowing a smaller power back-off than the original PA, which in turn improves the PA power efficiency. Power amplifier linearization has been widely studied. Available techniques include feedback, feedforward, and predistortion [2][3][4][5].Feedback is widely used in control systems. In the context of PA linearization, if we can extract the error signal as the difference between the (scaled) input and output to the PA, a negative feedback system can be constructed by feeding the error signal back to the PA input [6,7]. The gain-bandwidth trade-off and the instability problem, however, limit the feedback linearization performance of RF PAs, especially for wide-band applications.Feedforward linearization reproduces the error signal and compensates for it at the PA output [8]. In contrast, with feedback linearization, the compensation takes place at the Digital Front-End in Wireless Communications and Broadcasting, ed. Fa-

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“…At each supply voltage, a power sweep was conducted and PAE and Gain were measured. Applying a simple model, as described in [13], the ET performance was estimated. The model had a linear relationship between input power and drain voltage.…”

Section: Envelope Trackingmentioning

confidence: 99%

Optimization of Gallium nitride high power technology for commercial and military applications

Shealy¹,

Lefevre²,

Anderson³

et al. 2009

2009 IEEE Bipolar/BiCMOS Circuits and Technology Meeting

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Next generation commercial and military systems require high power amplifiers (HPAs) with superior performance such as higher efficiency, improved thermal performance, wider bandwidth and higher output power. Using an optimized 0.5um, 48V GaN-on-SiC process, a family of GaN power amplifiers are developed for applications in the frequency range of 30MHz to 4GHz and output power ranging from 8W to 500W.Such devices clearly demonstrate superior power-bandwidth product of GaN for military applications such as radar, military communications and electronic warfare. For commercial applications, a family of linear amplifiers, applicable to 3GPP, LTE and WiMax cellular base stations, offer high efficiency operation. Finally, an optimized GaN process is utilized to develop new cable TV power doubler modules offering 6dB improvement in CIN performance over incumbent GaAs based amplifiers.

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Augmented behavioral characterization for modeling the nonlinear response of power amplifiers

Cited by 32 publications

References 7 publications

Simulation and measurement-based X-parameter models for power amplifiers with envelope tracking

Simulation and measurement-based X-parameter models for power amplifiers with envelope tracking

Adaptive digital baseband predistortion

Optimization of Gallium nitride high power technology for commercial and military applications

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