- 标题
- 摘要
- 关键词
- 实验方案
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Dynamic Behavioral Modeling of RF Power Amplifier Based on Time-Delay Support Vector Regression
摘要： A new, dynamic behavioral modeling technique, based on a time-delay support vector regression (SVR) method, is presented in this paper. As an advanced machine learning algorithm, the SVR method provides an effective option for behavioral modeling of radio frequency (RF) power amplifiers (PAs), taking into account the effects of both device nonlinearity and memory. The basic theory of the proposed modeling technique is given, along with a detailed model extraction procedure. Unlike traditional artificial neural network (ANN) techniques, which take time to determine the best configuration of the model, the SVR method can obtain the optimal model in short time, using the grid-search technique. An example of an optimal SVR model selection applied to an RF PA is also given; the performance of the selected model presents a big improvement when compared with the default SVR model. Experimental validation is performed using an LDMOS PA, a single device gallium nitride (GaN) PA, and a Doherty GaN PA, revealing that the new modeling methodology provides very efficient and extremely accurate prediction. Compared with traditional Volterra models, canonical piecewise linear models, and ANN-based models, the proposed SVR model gives improved performance with reasonable complexity. In addition, it is shown that the model can predict accurately the behavior of the PA under input power levels that are different from those under which it is extracted.
关键词： time delay,radio frequency (RF) power amplifiers (PAs),machine learning,Dynamic behavioral model,support vector regression (SVR)
更新于2025-09-23 15:23:52
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[IEEE 2018 IEEE 38th International Conference on Electronics and Nanotechnology (ELNANO) - Kiev (2018.4.24-2018.4.26)] 2018 IEEE 38th International Conference on Electronics and Nanotechnology (ELNANO) - Experimental Characterization of Graphene Thick Films
摘要： While the plasmonic nature of graphene at terahertz frequencies has been widely reported, investigations on the practical utility of graphene at the microwave frequencies are sparse. In this paper, an ink comprising graphene thick films of different concentrations (12.5 wt.%, 25 wt.% and 33 wt.%) is prepared for deposition, by screen printing. Detailed investigation of the surface morphology of the films using SEM and AFM reveals that the graphene films present a homogeneous dispersion of the filler with a comparatively lower surface roughness at higher concentrations, and negligible agglomerates. The films are then printed in between copper electrodes on FR-4 substrate, commonly used in RF circuits, and the measured scattering parameters analyzed.
关键词： screen printing,radio frequency (RF),graphene,thick films,surface morphology
更新于2025-09-23 15:23:52
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[IEEE 2019 International Conference on Electrotechnical Complexes and Systems (ICOECS) - Ufa, Russia (2019.10.21-2019.10.25)] 2019 International Conference on Electrotechnical Complexes and Systems (ICOECS) - Energy efficiency improvement of OFDM-based Radio-over-fiber systems enabled with PAPR decrease method
摘要： The roadmap evolution and historical milestones of electromagnetic energy conversion techniques and related breakthroughs over the years are reviewed and presented with particular emphasis on low-density energy-harvest technologies. Electromagnetic sources responsible for the presence of ambient radio-frequency (RF) energy are examined and discussed. The effective use and recycling of such an ambient electromagnetic energy are the most relevant and critical issue for the current and future practicability of wireless energy-harvesting devices and systems. In this paper, a set of performance criteria and development considerations, required to meet the need of applications of ambient electromagnetic energy harvesting, are also derived from the radiating source analysis. The criteria can be calculated from a simple measurement of the I–V nonlinear behavior of RF rectification devices such as diodes and transistors, as well as linear frequency behavior (S-parameters). The existing rectifying devices are then reviewed in light of the defined performance criteria. Finally, a technological outlook of the performances that can be expected from different device technologies is assessed and discussed. Since the proposed spindiode technology would present the most promising device platform in the development of the most useful ambient energy harvesters, a special highlight of this disruptive scheme is provided in the presentation of this work.
关键词： diodes,metal–insulator–metal (MIM),spindiode,magnetic tunnel junction (MTJ),energy harvesting,Schottky diode,crystal rectifier,Ambient radio-frequency (RF) energy,backward diode
更新于2025-09-23 15:19:57
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[IEEE 2019 International Conference on Communication and Electronics Systems (ICCES) - Coimbatore, India (2019.7.17-2019.7.19)] 2019 International Conference on Communication and Electronics Systems (ICCES) - Internet of Things (IoT) enabled Sustainable Home Automation along with Security using Solar Energy
摘要： This paper presents a novel method for tracking the position of a medical instrument’s tip. The system is based on phase locking a high frequency signal transmitted from the medical instrument’s tip to a reference signal. Displacement measurement is established having the loop open, in order to get a low frequency voltage representing the medical instrument’s movement; therefore, positioning is established by means of conventional measuring techniques. The voltage-controlled oscillator stage of the phase-locked loop (PLL), combined to an appropriate antenna, comprises the associated transmitter located inside the medical instrument tip. All the other low frequency PLL components, low noise amplifier and mixer, are located outside the human body, forming the receiver part of the system. The operating details of the proposed system were coded in Verilog-AMS. Simulation results indicate robust medical instrument tracking in 1-D. Experimental evaluation of the proposed position tracking system is also presented. The experiments described in this paper are based on a transmitter moving opposite a stationary receiver performing either constant velocity or uniformly accelerated movement, and also together with two stationary receivers performing constant velocity movement again. This latter setup is implemented in order to demonstrate the prototype’s accuracy for planar (2-D) motion measurements. Error analysis and time-domain analysis are presented for system performance characterization. Furthermore, preliminary experimental assessment using a saline solution container to more closely approximate the human body as a radio frequency wave transmission medium has proved the system’s capability of operating underneath the skin.
关键词： radio frequency (RF),Displacement measurement,position tracking,medical instrument,phase shift
更新于2025-09-23 15:19:57
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[IEEE 2019 5th International Conference on Advances in Electrical Engineering (ICAEE) - Dhaka, Bangladesh (2019.9.26-2019.9.28)] 2019 5th International Conference on Advances in Electrical Engineering (ICAEE) - Structural properties of bi-layer Molybdenum Thin-film deposited by RF magnetron sputtering for CZTS solar cells
摘要： This paper presents a novel method for tracking the position of a medical instrument’s tip. The system is based on phase locking a high frequency signal transmitted from the medical instrument’s tip to a reference signal. Displacement measurement is established having the loop open, in order to get a low frequency voltage representing the medical instrument’s movement; therefore, positioning is established by means of conventional measuring techniques. The voltage-controlled oscillator stage of the phase-locked loop (PLL), combined to an appropriate antenna, comprises the associated transmitter located inside the medical instrument tip. All the other low frequency PLL components, low noise amplifier and mixer, are located outside the human body, forming the receiver part of the system. The operating details of the proposed system were coded in Verilog-AMS. Simulation results indicate robust medical instrument tracking in 1-D. Experimental evaluation of the proposed position tracking system is also presented. The experiments described in this paper are based on a transmitter moving opposite a stationary receiver performing either constant velocity or uniformly accelerated movement, and also together with two stationary receivers performing constant velocity movement again. This latter setup is implemented in order to demonstrate the prototype’s accuracy for planar (2-D) motion measurements. Error analysis and time-domain analysis are presented for system performance characterization. Furthermore, preliminary experimental assessment using a saline solution container to more closely approximate the human body as a radio frequency wave transmission medium has proved the system’s capability of operating underneath the skin.
关键词： radio frequency (RF),Displacement measurement,position tracking,medical instrument,phase shift
更新于2025-09-19 17:13:59
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[IEEE 2019 International Conference on Power Electronics Applications and Technology in Present Energy Scenario (PETPES) - Mangalore, India (2019.8.29-2019.8.31)] 2019 International Conference on Power Electronics Applications and Technology in Present Energy Scenario (PETPES) - Performance Comparison of Root-finding Algorithms for Solar Photovoltaic Emulator
摘要： This paper presents a novel method for tracking the position of a medical instrument’s tip. The system is based on phase locking a high frequency signal transmitted from the medical instrument’s tip to a reference signal. Displacement measurement is established having the loop open, in order to get a low frequency voltage representing the medical instrument’s movement; therefore, positioning is established by means of conventional measuring techniques. The voltage-controlled oscillator stage of the phase-locked loop (PLL), combined to an appropriate antenna, comprises the associated transmitter located inside the medical instrument tip. All the other low frequency PLL components, low noise amplifier and mixer, are located outside the human body, forming the receiver part of the system. The operating details of the proposed system were coded in Verilog-AMS. Simulation results indicate robust medical instrument tracking in 1-D. Experimental evaluation of the proposed position tracking system is also presented. The experiments described in this paper are based on a transmitter moving opposite a stationary receiver performing either constant velocity or uniformly accelerated movement, and also together with two stationary receivers performing constant velocity movement again. This latter setup is implemented in order to demonstrate the prototype’s accuracy for planar (2-D) motion measurements. Error analysis and time-domain analysis are presented for system performance characterization. Furthermore, preliminary experimental assessment using a saline solution container to more closely approximate the human body as a radio frequency wave transmission medium has proved the system’s capability of operating underneath the skin.
关键词： radio frequency (RF),medical instrument,Displacement measurement,phase shift,position tracking
更新于2025-09-19 17:13:59
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[IEEE 2019 IEEE Research and Applications of Photonics in Defense Conference (RAPID) - Miramar Beach, FL, USA (2019.8.19-2019.8.21)] 2019 IEEE Research and Applications of Photonics in Defense Conference (RAPID) - Multispectral Plasmonic Perfect Absorbers Integrated with Room-Temperature VO <sub/>x</sub> Air-Bridge Bolometers
摘要： The roadmap evolution and historical milestones of electromagnetic energy conversion techniques and related breakthroughs over the years are reviewed and presented with particular emphasis on low-density energy-harvest technologies. Electromagnetic sources responsible for the presence of ambient radio-frequency (RF) energy are examined and discussed. The effective use and recycling of such an ambient electromagnetic energy are the most relevant and critical issue for the current and future practicability of wireless energy-harvesting devices and systems. In this paper, a set of performance criteria and development considerations, required to meet the need of applications of ambient electromagnetic energy harvesting, are also derived from the radiating source analysis. The criteria can be calculated from a simple measurement of the I–V nonlinear behavior of RF rectification devices such as diodes and transistors, as well as linear frequency behavior (S-parameters). The existing rectifying devices are then reviewed in light of the defined performance criteria. Finally, a technological outlook of the performances that can be expected from different device technologies is assessed and discussed. Since the proposed spindiode technology would present the most promising device platform in the development of the most useful ambient energy harvesters, a special highlight of this disruptive scheme is provided in the presentation of this work.
关键词： Schottky diode,magnetic tunnel junction (MTJ),energy harvesting,diodes,spindiode,backward diode,metal–insulator–metal (MIM),crystal rectifier,Ambient radio-frequency (RF) energy
更新于2025-09-19 17:13:59
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Single-Mode 940 nm VCSELs With Narrow Divergence Angles and High-Power Performances for Fiber and Free-Space Optical Communications
摘要： This paper presents a novel method for tracking the position of a medical instrument’s tip. The system is based on phase locking a high frequency signal transmitted from the medical instrument’s tip to a reference signal. Displacement measurement is established having the loop open, in order to get a low frequency voltage representing the medical instrument’s movement; therefore, positioning is established by means of conventional measuring techniques. The voltage-controlled oscillator stage of the phase-locked loop (PLL), combined to an appropriate antenna, comprises the associated transmitter located inside the medical instrument tip. All the other low frequency PLL components, low noise amplifier and mixer, are located outside the human body, forming the receiver part of the system. The operating details of the proposed system were coded in Verilog-AMS. Simulation results indicate robust medical instrument tracking in 1-D. Experimental evaluation of the proposed position tracking system is also presented. The experiments described in this paper are based on a transmitter moving opposite a stationary receiver performing either constant velocity or uniformly accelerated movement, and also together with two stationary receivers performing constant velocity movement again. This latter setup is implemented in order to demonstrate the prototype’s accuracy for planar (2-D) motion measurements. Error analysis and time-domain analysis are presented for system performance characterization. Furthermore, preliminary experimental assessment using a saline solution container to more closely approximate the human body as a radio frequency wave transmission medium has proved the system’s capability of operating underneath the skin.
关键词： position tracking,Displacement measurement,phase shift,radio frequency (RF),medical instrument
更新于2025-09-19 17:13:59
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[IEEE 2019 IEEE 32nd International Conference on Micro Electro Mechanical Systems (MEMS) - Seoul, Korea (South) (2019.1.27-2019.1.31)] 2019 IEEE 32nd International Conference on Micro Electro Mechanical Systems (MEMS) - High-Frequency Hexagonal Boron Nitride (h-BN) Phononic Waveguides
摘要： This digest paper presents the first experimental demonstration of nanoscale phononic waveguides based on a two-dimensional (2D) layered crystalline material, namely hexagonal boron nitride (h-BN). Taking advantage of the planar geometry, the challenges in nanofabrication of 2D materials can be circumvented through a heterogeneous integration approach. Rich wave propagation characteristics of h-BN phononic waveguides are revealed in both finite element method (FEM) simulations and transmission measurements. Numerical analysis further indicates that the frequency response of the designed h-BN phononic waveguides can be finely tuned by varying the thickness or tension level of the h-BN crystals, across the high frequency (HF, 3?30 MHz) to very high frequency (VHF, 30?300 MHz) bands. Manipulation and guiding of high frequency mechanical waves on integratable 2D device platforms will open new opportunities in radio-frequency (RF) signal processing and on-chip quantum information technologies.
关键词： phononic waveguides,very high frequency (VHF),radio-frequency (RF) signal processing,quantum information technologies,high frequency (HF),hexagonal boron nitride (h-BN)
更新于2025-09-12 10:27:22
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[IEEE 2019 IEEE Wireless Communications and Networking Conference (WCNC) - Marrakesh, Morocco (2019.4.15-2019.4.18)] 2019 IEEE Wireless Communications and Networking Conference (WCNC) - A Robust and Energy Efficient NOMA-Enabled Hybrid VLC/RF Wireless Network
摘要： The present work investigates the performance of non-orthogonal multiple access (NOMA) in a hybrid visible light communication (VLC)/radio frequency (RF) wireless network. In particular, we investigate the energy efficiency of the proposed architecture assuming imperfect channel state information (CSI), which is a realistic assumption that is encountered in practical indoor and outdoor wireless communication scenarios. We demonstrate that the performance of the proposed scheme in terms of energy efficiency outperforms by four-fold the corresponding performance of its orthogonal frequency division multiple access (OFDMA) counterpart. In addition, it is shown that the energy efficiency of the proposed scheme is more robust to CSI errors and line of sight (LOS) variations than the OFDMA-based scheme, which appears to be more susceptible to the CSI error and the LOS availability probability. Finally, our findings reveal that the performance gain of NOMA over OFDMA in the considered hybrid VLC/RF setup is directly proportional to the probability of LOS availability. These results are expected to be useful in the efficient design and efficient operation of hybrid VLC/RF wireless systems.
关键词： Non-orthogonal multiple access (NOMA),Energy efficiency,Channel state information (CSI),Radio frequency (RF),Visible light communication (VLC),Hybrid wireless network
更新于2025-09-12 10:27:22