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Exact Outage Probability Analysis of the Mixed RF/FSO System with Variable Gain Relays
摘要： This paper presents an uni?ed analysis of the mixed radio-frequency/free-space optics (RF/FSO) relaying system, with multiple variable gain amplify-and-forward relays. The partial relay selection (PRS) is employed to select the active relay for further re-transmission. Due to fast fading statistics of the ?rst RF hop, it is assumed that the channel state information of the RF link is outdated, which is used for both relay gain adjustment and PRS procedure. The RF hops are subject to the Rayleigh fading, while the FSO hop is affected by the atmospheric turbulence and the pointing errors. The intensity ?uctuations of the optical signal caused by atmospheric turbulence are modeled by general M′alaga (M) distribution, which takes into account effect of multiple scattered components. Exact expression for the outage probability is derived. In addition, high signal-to-noise ratio approximations are provided, which can be used to ef?ciently determine the outage probability ?oor. Numerical results are validated by Monte Carlo simulations, which are used to examine the effects of the system and channel parameters on the RF/FSO system performance.
关键词： Free-space optical systems,partial relay selection,variable gain relays,outage probability,outdated channel state information,radio frequency systems
更新于2025-09-11 14:15:04
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Four-PAM Modulation of Ambient FM Backscattering for Spectrally Efficient Low-Power Applications
摘要： Ambient backscatter uses radio frequency signals available in the environment (e.g., radio broadcasting, television, or mobile telephony) to transmit data effectively leading to significant energy and cost efficiency increase. This paper presents a novel wireless tag, which for the first time utilizes 4-pulse amplitude modulation technique to modulate the ambient backscattered FM signals in order to send data to a nearby low-cost software defined radio reader. The tag is based on an RF front-end that uses a single transistor controlled by an ultralow-power microcontroller. The microcontroller includes an analog-to-digital converter for sensing and a digital-to-analog converter for RF front-end control. A proof-of-concept prototype is demonstrated in an indoor environment with the low bit rate of 345 b/s and power consumption 27 μW. It operated using a real FM station at 34.5 km away and the tag-to-reader distance was tested at 1 m. The value of energy spent in this modulator was 78.2 nJ/bit at 345 b/s and 27.7 nJ/bit at 10.2 kb/s.
关键词： Internet-of-Things (IoT),backscatter communication,Ambient backscattering,software-defined radio (SDR),pulse amplitude modulation (PAM),FM modulation,radio frequency identification (RFID) sensors
更新于2025-09-10 09:29:36
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[IEEE 2018 IEEE International Conference on Electron Devices and Solid State Circuits (EDSSC) - Shenzhen (2018.6.6-2018.6.8)] 2018 IEEE International Conference on Electron Devices and Solid State Circuits (EDSSC) - High Performance Double-Gate Graphene Radio-Frequency Transistors
摘要： Despite the demonstrated high current gain cutoff frequency (fT), most graphene transistors show significantly lower maximum oscillation frequency (fmax), which is a crucial figure of merit that determines the transistors’ power amplification ability. This work presents a new graphene device structure with double-gate synchronously control the graphene channel. The structure possesses several advantages over conventional top gate structures, including low gate resistance and high on/off ratio. fmax ~ 50% higher than fT is achieved from devices with different gate length.
关键词： double-gate,radio frequency (RF),graphene,fmax
更新于2025-09-10 09:29:36
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Mesoporous titania-coated biosensor and FEM model design for highly sensitive detection of low molecular weight targets
摘要： This paper presents the interest of a highly sensitive biosensor coated with a TiO2 mesoporous film as sensitive layer. The main novelty is related to the modelling of the device and simulation by using Finite Element Method with COMSOL Multiphysics software, as a good way to take into account the physical properties of porous 3D-layers. The strategy of using such Love wave devices, with 3D porous layers, offering further easy functionalization, aims not only to increase the amount of targets caught on the sensor surface, but also to enhance the detection mechanism by a higher perturbation of the Love wave acoustic energy which could be trapped inside the 3D sensitive layer. First, as a proof of concept, experimental devices with a 3D titania mesoporous layer were realized, and they have shown a good agreement with simulated results. Furthermore, experimental test with several Newtonian liquids are investigated, in a range of viscosities from 1 to 7 cP, typical of those concerned by our biochemical applications. The sensitivity with a 300 nm thick porous sensing layer was 10 times that of the bare device, with interesting dynamical issues to be further studied, giving rise to the great potentialities of such architectures for biological detection of low weight biochemical targets.
关键词： surface to volume ratio,mesoporous materials,biochemical sensing,Radio Frequency Love wave device,finite element modelling,acoustic interaction in liquid medium
更新于2025-09-10 09:29:36
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Directly Printable Frequency Signature Chipless RFID Tag for IoT Applications
摘要： This paper proposes a low-cost, compact, flexible passive chipless RFID tag that has been designed and analyzed. The tag is a bowtie-shaped resonator based structure with 36 slots; where each patch is loaded with 18 slots. The tag is set in a way that each slot in a patch corresponds to a metal gap in the other patch. Hence there is no mutual interference, and high data capacity of 36 bits is achieved in such compact size. Each slot corresponds to a resonance frequency in the RCS curve, and each resonance corresponds to a bit. The tag has been realized for Taconic TLX-0, PET, and Kapton?HN (DuPontTM) substrates with copper, aluminum, and silver nanoparticle-based ink (Cabot CCI-300) as conducting materials. The tag exhibits flexibility and well optimized while remaining in a compact size. The proposed tag yields 36 bits in a tag dimension of 24.5 × 25.5 mm2. These 36 bits can tag 236 number of objects/items. The ultimate high capacity, compact size, flexible passive chipless RFID tag can be arrayed in various industrial and IoT-based applications.
关键词： Radio Frequency Identification (RFID),Radar Cross-Section (RCS),backscattering,Chipless
更新于2025-09-10 09:29:36
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[IEEE 2018 Conference on Precision Electromagnetic Measurements (CPEM 2018) - Paris, France (2018.7.8-2018.7.13)] 2018 Conference on Precision Electromagnetic Measurements (CPEM 2018) - Null Technique for Precision RF Phase Shift Measurements
摘要： A dual channel IF substitution null system is developed for precision phase shift measurements and standards in frequency ranges of 1 MHz to 1 GHz. A particular programmable IF phase shifter equipped with a calibrated phase monitor is used as a phase reference standard. High sensitivity nature of the null technique provides accurate measurements to the DUT even with large attenuation. Measurement resolutions of 0.002 deg., 0.006 deg., and 0.023 deg. were obtained for DUT with attenuation of 20 dB, 40 dB, and 60 dB, respectively, at 1 GHz.
关键词： Phase measurement,uncertainty,radio frequency,precision measurements,attenuation measurement,phase shifters
更新于2025-09-10 09:29:36
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[IEEE 2018 Conference on Precision Electromagnetic Measurements (CPEM 2018) - Paris, France (2018.7.8-2018.7.13)] 2018 Conference on Precision Electromagnetic Measurements (CPEM 2018) - SIM Key Comparison of S-Parameters SIM.EM.RF-K5b.CL
摘要： The first RF key comparison within the Inter-American Metrology System (SIM) Regional Metrology Organization has been carried out. The purpose of it was to establish the degree of equivalence of scattering parameters measurements of both 1-port and 2-port coaxial devices among national metrology institutes (NMIs) that belong to SIM region and in support of CIPM Mutual Recognition Agreement (MRA). The travelling standards were four devices with Type-N coaxial connectors and 50 ? of characteristic impedance: a matched load, a mismatched load and two attenuators of 3 dB and 20 dB. Four SIM institutes participated in the comparison as well as NPLI.
关键词： measurement standards,measurement uncertainty,measurement techniques,Measurement,radio frequency,precision measurements,scattering parameters
更新于2025-09-10 09:29:36
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[IEEE 2018 International Russian Automation Conference (RusAutoCon) - Sochi, Russia (2018.9.9-2018.9.16)] 2018 International Russian Automation Conference (RusAutoCon) - Reliability Prediction of Radio Frequency Identification Passive Tags Power Supply Systems Based on A<inf>3</inf>B<inf>5</inf> Resonant-Tunneling Diodes
摘要： The methodology of predicting radio frequency identification (RFID) passive tag power supply system reliability is developed. The reliability of a RFID passive tag power supply system is estimated in terms of a parametric failure associated with the I-V characteristics drift of resonant-tunneling diodes (RTD) that are a part of the tag rectifier under the influence of external factors beyond the tolerance limits. The methodology of the time to failure of the RFID passive tag power supply system calculation by the criterion of the minimum permissible range is presented. The developed methodology can be used in the design of RFID systems with passive UHF and SHF tags to predict their reliability under specified operating conditions. The developed algorithms and software modules can be integrated into the corresponding CAD systems.
关键词： passive tag,resonant-tunneling diode,degradation,radio frequency identification,I-V characteristic,reliability,power supply system
更新于2025-09-10 09:29:36
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Compact Scalable Modeling of Chipless RFID Tag Based on High-Impedance Surface
摘要： This paper proposes a compact model for chipless radio frequency identification (RFID) tag. This compact scalable model consists of capacitors, inductors, and resistors of which their values are directly described by the physical dimension of the chipless tag. Moreover, based on this compact model, radar cross section of chipless RFID tag is predicted, by analyzing polarizability based on surface current distribution in different modes. To validate the proposed model, a 5-bit chipless RFID tag based on high-impedance surface (HIS) is presented, with good agreement among modeled, simulated, and measured results. A wide range of physical parameters have also been validated to show the scalability. This compact scalable model of chipless RFID tag not only simplifies the tag design, but also provides an insight understanding of the HIS structure.
关键词： radar cross section (RCS),high-impedance surface (HIS),equivalent circuit modeling,Chipless radio frequency identification (RFID) tag,surface current distribution
更新于2025-09-10 09:29:36
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Cryogenic Characterization of 22nm FDSOI CMOS Technology for Quantum Computing ICs
摘要： An approach is proposed to realize large-scale, “high-temperature” and high-fidelity quantum computing ICs based on single- and multiple coupled quantum-dot electron- and hole-spin qubits monolithically integrated with the mm-wave spin manipulation and readout circuitry technology. Measurements of minimum-size 6nmx20nmx80nm Si-channel n-MOSFETs (electron-spin qubit), SiGe-channel p-MOSFETs (hole-spin qubit), and double quantum-dot complementary qubits reveal strong quantum effects in the subthreshold region at 2 K, characteristic of resonant tunneling in a quantum dot. S-parameter measurements of a transimpedance amplifier (TIA) for spin readout show improved performance from 300 K to 2 K. Finally, the qubit-with-TIA circuit has 50Ω output impedance, 78dBΩ transimpedance gain with unity-gain bandwidth of 70 GHz and consumes 3.1 mW.
关键词： CMOS,silicon-on-insulator,quantum information processing,radio frequency,monolithic integrated circuits,semiconductor quantum dots,silicon,cryogenics
更新于2025-09-10 09:29:36