- 标题
- 摘要
- 关键词
- 实验方案
- 产品
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A Square-Root-Based Memory Polynomial Model for Concurrent Dual-Band Digital Predistortion
摘要： In this letter, a novel 2-D square-root-based memory polynomial behavioral model is proposed. A new set of square-root-based basic functions is adopted to describe the characteristic of the predistorter. Since the proposed model has only two nested summations, the number of coefficients of the proposed model is greatly reduced compared with models which have three nested summations. The experimental results show that the proposed model can reduce the coefficients by more than 66.7% compared with the 2-D digital predistortion (2D-DPD) model. Moreover, the proposed model can achieve better adjacent channel power ratio (ACPR) performance. Compared with the 2D-DPD model and the simple online coefficient update model, the proposed model can improve the normalized mean-square error by 11 dB. Compared with the 2-D modified memory polynomial model, the proposed model can obtain similar ACPR performance with a shorter running time.
关键词： power amplifiers (PAs),Digital predistortion (DPD),dual band
更新于2025-09-23 15:22:29
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[IEEE 2019 IEEE Conference on Antenna Measurements & Applications (CAMA) - Kuta, Bali, Indonesia (2019.10.23-2019.10.25)] 2019 IEEE Conference on Antenna Measurements & Applications (CAMA) - Measurement of Complex Permittivity of Tissue-Equivalent Liquid Poured in a Waveguide Well
摘要： A method to characterize the memory effects in a nonlinear concurrent dual-band transmitter is presented. It is an extension of the conventional two-tone test for power amplifiers to concurrent dual-band transmitters. The output signal of a concurrent dual-band transmitter is affected not only by intermodulation (IM) products but also by cross-modulation (CM) products. In one frequency band, the transmitter is excited by a two-tone signal which frequency separation is swept. In the second band, the transmitter is concurrently excited by another two-tone signal with slightly wider frequency separation. The frequency difference of the two signals is fixed during the frequency sweep. The two-tone test is made at different power levels. The upper and lower third-order IM and CM products are measured. The asymmetry between the upper and lower the third-order transmitter’s memory effects. The measurement results show that the memory effects are more dominant in the third-order IM products than in the CM products. An error analysis and system calibration was performed and measurement results for two different devices are presented.
关键词： cross modulation (CM),dual band,digital predistortion (DPD),multiple input multiple output (MIMO),Amplifier,power amplifier (PA),intermodulation (IM)
更新于2025-09-23 15:19:57
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[IEEE 2019 44th International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz) - Paris, France (2019.9.1-2019.9.6)] 2019 44th International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz) - Synchronous Pumping Terahertz Parametric Oscillator Driven by Amplified Picosecond Mode-locked Laser
摘要： This paper analyzes the effects of load impedance mismatch in power ampli?ers which linearity has been enhanced using various digital predistortion (DPD) algorithms. Two different power ampli?er architectures are considered: a class AB and a Doherty ampli?er and three model structures for the DPD model are compared: memoryless polynomial (MLP), general memory polynomial (GMP) and Kautz-Volterra functions (KV). This paper provides a sensitivity analysis of the linearized ampli?ers under load mismatch conditions and reports the performance when dynamic parameter identi?cation for the DPD is used to compensate for the changes in the load impedance. In general, power ampli?ers linearity is sensitive to load impedance mismatch. Linearity may degrade as much as 10 dB (in normalized mean square error) according to the magnitude and the phase of the re?ection coef?cient provided by the load impedance. However, depending on the ampli?er design, the sensitivity to load impedance mismatch varies. While the Doherty ampli?er studied show signi?cant linearity degradations in the in-band and out-of-band distortions, the out-of-band distortions of the studied class AB were less sensitive to the load impedance mismatch. In adaptive DPD schemes, the performance obtained in the MLP model does not bene?t from the updating scheme and the performance achieved is similar to a static case, where no updates are made. This stresses the memory requirements in the predistorter. When employing the GMP and the KV models in an adaptive DPD scheme, they tackle to a larger extent the linearity degradations due to load impedance mismatch.
关键词： load impedance,Digital predistortion,power ampli?ers,impedance mismatch
更新于2025-09-19 17:13:59
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[IEEE 2019 IEEE/CVF International Conference on Computer Vision Workshop (ICCVW) - Seoul, Korea (South) (2019.10.27-2019.10.28)] 2019 IEEE/CVF International Conference on Computer Vision Workshop (ICCVW) - Adaptive Ptych: Leveraging Image Adaptive Generative Priors for Subsampled Fourier Ptychography
摘要： An instrumentation, measurement post-processing technique is presented to characterize transmitters by multiple input multiple output (MIMO) Volterra series. The MIMO Volterra series is decomposed as the sum of nonlinear single-variable self-kernels and a multi-variable cross-kernel. These kernels are identified by sample averages of the outputs using inputs of different sample periodicity. This technique is used to study the HW effects in a RF MIMO transmitter composed by input and output coupling filters (cross-talk) sandwiching a non-linear amplification stage. The proposed technique has shown to be useful in identifying the dominant effects in the transmitter structure and it can be used to design behavioral models and compensation techniques.
关键词： linearization,concurrent,MIMO Volterra series,MIMO,digital predistortion,behavioral modeling,Amplifiers
更新于2025-09-19 17:13:59
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[IEEE 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Chicago, IL, USA (2019.6.16-2019.6.21)] 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Performance of Soiled PV Module Technologies: Behavior Based on Controverted Parameters
摘要： An instrumentation, measurement post-processing technique is presented to characterize transmitters by multiple input multiple output (MIMO) Volterra series. The MIMO Volterra series is decomposed as the sum of nonlinear single-variable self-kernels and a multi-variable cross-kernel. These kernels are identified by sample averages of the outputs using inputs of different sample periodicity. This technique is used to study the HW effects in a RF MIMO transmitter composed by input and output coupling filters (cross-talk) sandwiching a non-linear amplification stage. The proposed technique has shown to be useful in identifying the dominant effects in the transmitter structure and it can be used to design behavioral models and compensation techniques.
关键词： linearization,digital predistortion,MIMO Volterra series,MIMO,concurrent,Amplifiers,behavioral modeling
更新于2025-09-19 17:13:59
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[IEEE 2019 Chinese Automation Congress (CAC) - Hangzhou, China (2019.11.22-2019.11.24)] 2019 Chinese Automation Congress (CAC) - The Photovoltaic Intelligent Grid-connection System Based on Module Cascade Topology
摘要： An instrumentation, measurement post-processing technique is presented to characterize transmitters by multiple input multiple output (MIMO) Volterra series. The MIMO Volterra series is decomposed as the sum of nonlinear single-variable self-kernels and a multi-variable cross-kernel. These kernels are identified by sample averages of the outputs using inputs of different sample periodicity. This technique is used to study the HW effects in a RF MIMO transmitter composed by input and output coupling filters (cross-talk) sandwiching a non-linear amplification stage. The proposed technique has shown to be useful in identifying the dominant effects in the transmitter structure and it can be used to design behavioral models and compensation techniques.
关键词： MIMO Volterra series,MIMO,digital predistortion,behavioral modeling,linearization,Amplifiers,concurrent
更新于2025-09-16 10:30:52
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[IEEE 2019 IEEE Transportation Electrification Conference and Expo, Asia-Pacific (ITEC Asia-Pacific) - Seogwipo-si, Korea (South) (2019.5.8-2019.5.10)] 2019 IEEE Transportation Electrification Conference and Expo, Asia-Pacific (ITEC Asia-Pacific) - Technical Evaluation of Utility-Interactive Photovoltaic Power Generation System with Energy Storage based on the Experimental Setup
摘要： This paper analyzes the effects of load impedance mismatch in power ampli?ers which linearity has been enhanced using various digital predistortion (DPD) algorithms. Two different power ampli?er architectures are considered: a class AB and a Doherty ampli?er and three model structures for the DPD model are compared: memoryless polynomial (MLP), general memory polynomial (GMP) and Kautz-Volterra functions (KV). This paper provides a sensitivity analysis of the linearized ampli?ers under load mismatch conditions and reports the performance when dynamic parameter identi?cation for the DPD is used to compensate for the changes in the load impedance. In general, power ampli?ers linearity is sensitive to load impedance mismatch. Linearity may degrade as much as 10 dB (in normalized mean square error) according to the magnitude and the phase of the re?ection coef?cient provided by the load impedance. However, depending on the ampli?er design, the sensitivity to load impedance mismatch varies. While the Doherty ampli?er studied show signi?cant linearity degradations in the in-band and out-of-band distortions, the out-of-band distortions of the studied class AB were less sensitive to the load impedance mismatch. In adaptive DPD schemes, the performance obtained in the MLP model does not bene?t from the updating scheme and the performance achieved is similar to a static case, where no updates are made. This stresses the memory requirements in the predistorter. When employing the GMP and the KV models in an adaptive DPD scheme, they tackle to a larger extent the linearity degradations due to load impedance mismatch.
关键词： power ampli?ers,Digital predistortion,impedance mismatch,load impedance
更新于2025-09-16 10:30:52
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Partial Least Squares Identification of Multi Look-Up Table Digital Predistorters for Concurrent Dual-Band Envelope Tracking Power Amplifiers
摘要： This paper presents a technique to estimate the coefficients of a multiple-look-up table (LUT) digital predistortion (DPD) architecture based on the partial least-squares (PLS) regression method. The proposed 3-D distributed memory LUT architecture is suitable for efficient FPGA implementation and compensates for the distortion arising in concurrent dual-band envelope tracking power amplifiers. On the one hand, a new variant of the orthogonal matching pursuit algorithm is proposed to properly select only the best LUTs of the DPD function in the forward path, and thus reduce the number of required coefficients. On the other hand, the PLS regression method is proposed to address both the regularization problem of the coefficient estimation and, at the same time, reducing the number of coefficients to be estimated in the DPD feedback identification path. Moreover, by exploiting the orthogonality of the PLS transformed matrix, the computational complexity of the parameters’ identification can be significantly simplified. Experimental results will prove how it is possible to reduce the DPD complexity (i.e., the number of coefficients) in both the forward and feedback paths while meeting the targeted linearity levels.
关键词： principal component analysis (PCA),look-up tables (LUTs),power amplifier (PA),envelope tracking (ET),partial least squares (PLS),Digital predistortion (DPD)
更新于2025-09-09 09:28:46
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Hybrid Analog/Digital Linearization of GaN HEMT-Based Power Amplifiers
摘要： In this paper, we describe a hybrid analog/digital linearization scheme for GaN high-electron-mobility transistor (HEMT)-based power ampli?ers that consists of a novel analog feedforward circuit and a conventional generalized memory polynomial (GMP) digital predistorter (DPD). The analog circuit implements a nonlinear ?lter that compensates the long-term memory effects observed in GaN HEMTs due to the self-biasing behavior caused by electron-trapping phenomena. Experimental tests demonstrate that this linearization scheme achieves a level of intermodulation distortion 6.8 dB better than what can be achieved with just the use of the GMP DPD. This level of distortion is in compliance with the linearity speci?cations for multicarrier Global System for Mobile communications base station transmitters.
关键词： Analog linearization,long-term memory effects,GaN high-electron-mobility transistor (HEMT),power ampli?er (PA) linearization,digital predistortion (DPD),electron trapping
更新于2025-09-09 09:28:46
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[IEEE 2018 IEEE MTT-S International Microwave Workshop Series on 5G Hardware and System Technologies (IMWS-5G) - Dublin (2018.8.30-2018.8.31)] 2018 IEEE MTT-S International Microwave Workshop Series on 5G Hardware and System Technologies (IMWS-5G) - A novel model of joint compensation for I/Q imbalance and nonlinearity in concurrent dual-band transmitters
摘要： I/Q impairments of the I/Q modulator can adversely affect the performance of wireless transmitters. This problem is much more pronounced in concurrent dual-band transmitters with two modulators involved. In this paper, we propose a hybrid two-box model, called HTB model, to jointly compensate I/Q imbalance of modulators and concurrent dual-band PA distortion. The proposed model is based on the characteristics of I/Q imbalance in the concurrent dual-band transmitters. It has much lower complexity and comparative linearization performance compared to conventional models. The experimental results demonstrate the superior performance of the proposed method.
关键词： Power Amplifiers,I/Q imbalance,Digital predistortion
更新于2025-09-09 09:28:46