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Design and measurement of a 5G mmW mobile backhaul transceiver at 28 GHz
摘要： High throughput and ultra low latency are the main requirements for fifth generation (5G) mobile broadband communications. Densely populated urban environments require utilization of previously underutilized millimeter wave frequency spectrum for higher data rates. The Ka-band, previously used in satellite applications, is of particular interest to terrestrial 5G mobile networks. New radio solutions are required for these frequencies, such as multiple wireless base stations organized in small cells and highly directional antennas to compensate for higher path loss. Wireless backhaul is predicted to be the most cost-effective and versatile solution to connect 5G base stations to the core network. Wireless backhaul enables flexible and easy installation of 5G base stations in ad hoc networks, supporting large crowd gatherings such as concerts and sports events. In this article, we present an architecture of a wireless backhaul transceiver, which operates on the 26.5–29.5-GHz band. The architecture described in this paper was implemented, and the performance of the receiver (Rx) array has been measured. We also present over-the-air antenna array measurement results using the Rx. The measurement results show that unequal Rx channel gains and antenna gains do not have a significant effect on the shape of the main lobe of the radiation pattern. We have measured a coherence gain of 2.7 dB from two Rx channels that is close to the theoretical value of 3.0 dB. We have achieved a conducted Rx EVM of better than 2% using a 100-MHz 16-QAM modulated signal at 26.5 GHz.
关键词： Antenna pattern,Beamforming,Millimeter wave,Radio frequency,Transceiver,5G,Antenna array,Backhaul
更新于2025-09-23 15:21:01
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Electron dynamics in low pressure capacitively coupled radio frequency discharges
摘要： In low temperature plasmas, the interaction of the electrons with the electric field is an important current research topic that is relevant for many applications. Particularly, in the low pressure regime ((cid:1)10 Pa), electrons can traverse a distance that may be comparable to the reactor dimensions without any collisions. This causes “nonlocal,” dynamics which results in a complicated space- and time-dependence and a strong anisotropy of the distribution function. Capacitively coupled radio frequency (CCRF) discharges, which operate in this regime, exhibit extremely complex electron dynamics. This is because the electrons interact with the space- and time-dependent electric field, which arises in the plasma boundary sheaths and oscillates at the applied radio frequency. In this tutorial paper, the fundamental physics of electron dynamics in a low pressure electropositive argon discharge is investigated by means of particle-in-cell/Monte Carlo collisions simulations. The interplay between the fundamental plasma parameters (densities, fields, currents, and temperatures) is explained by analysis (aided by animations) with respect to the spatial and temporal dynamics. Finally, the rendered picture provides an overview of how electrons gain and lose their energy in CCRF discharges.
关键词： low pressure,particle-in-cell/Monte Carlo collisions simulations,electron dynamics,plasma parameters,capacitively coupled radio frequency discharges
更新于2025-09-23 15:21:01
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Electrical features of radio-frequency atmospheric pressure helium discharge with and without dielectric electrodes
摘要： In this paper, a comparative study of radio-frequency atmospheric pressure glow discharge (rf APGD) generated in helium with and without dielectric electrodes to investigate the effect of electrodes insulation on electrical features of APGD, is presented. In α mode both the rf APGDs remain volumetric, stable and uniform. In γ mode the APGD without dielectric electrodes shrinks into a constricted plasma column whereas APGD with dielectric electrodes remains stable and retains the same volume without plasma constriction even at higher densities of discharge current. A comparison of electrical features of both rf APGDs in normal and abnormal glow discharge regimes is presented. In both APGDs with and without dielectric electrodes, impedance measurements have been performed and compared with equivalent circuit models. The measured impedance data is found to be in good agreement with simulated data.
关键词： dielectric electrodes,radio-frequency atmospheric pressure glow discharge,plasma stability control
更新于2025-09-23 15:21:01
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The effect of Zn3N2 phase decomposition on the properties of highly-doped ZnO: Al, N films
摘要： Study of Al-N simultaneous doping and thermal annealing influence on the properties of ZnO films is very important for achievement as p-type conductivity in the films as for improvement the performance of ZnO-based ultraviolet detectors. Highly-doped ZnO:Al,N films containing the Zn3N2 phase (ZnO:Al,N-Zn3N2) were grown on Si substrates by magnetron sputtering using a layer-by-layer growth technique. Our work presents a comparative study of the structure, optical and electronic properties of highly-doped as-grown and annealed ZnO:Al,N films. It was shown that the thermal annealing of ZnO:Al,N-Zn3N2 film at atmospheric conditions allows to decompose the Zn3N2 phase. The features of this phenomena on the properties of ZnO:Al,N films were investigated and discussed in detail by using X-ray diffraction, energy dispersive X-ray analysis, Raman scattering, photoluminescence, X-ray photoelectron spectroscopy and X-ray emission spectroscopy.
关键词： Radio-frequency magnetron sputtering,Zinc oxide,Nitrogen-aluminum doping,Photoluminescence,X-ray photoelectron spectroscopy,Thin films,X-ray diffraction,Raman scattering
更新于2025-09-23 15:21:01
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[OSA CLEO: Applications and Technology - San Jose, California (2015..-..)] CLEO: 2015 - Photonic generation of linearly-chirped microwave waveform with tunable center frequency and time-bandwidth product
摘要： A novel approach is presented to generate linearly-chirped microwave waveforms with tunable center frequency and expandable time-bandwidth product (TBWP). Different types of waveforms are demonstrated and the maximum measured TBWP is up to ~166.4.
关键词： Radio frequency photonics,Microwaves,Mode-locked lasers
更新于2025-09-23 15:21:01
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Detailed investigation of photoluminescence, structural, and elemental properties of ZnO thin films under various annealing ambient
摘要： Zinc oxide (ZnO) has extensively exploited the material in the field of optoelectronics due to its inherent wide bandgap and high electron mobility. Properties of ZnO is very sensitive to its deposition methods and conditions. We report the effect of annealing ambient (i.e. argon, nitrogen, oxygen, or vacuum) on the optical, structural and elemental properties of the RF-sputtered ZnO thin films. In this work, we have performed compressive study on the effects of annealing ambient on a donor-bound exciton peak, exciton-exciton and electron-exciton scattering using low temperature (18 K) photoluminescence measurement which is not yet well understood. We have reported dominant on the donor-bound exciton peak with the lowest full width half maximum value (~4.48 nm) for annealing in an oxygen ambient. The annealing ambient strongly influenced the elemental properties of the film and we have reported the reduction in oxygen vacancy with annealing in an oxygen ambient. This work showed that the influence of ex-situ annealing ambient on exciton emission of ZnO thin films and thus providing a tool for enhancing the optical and elemental properties of the film.
关键词： ZnO thin films,Radio-frequency sputtering,X-ray photoelectron spectroscopy,Rapid thermal processing,Photoluminescence
更新于2025-09-23 15:19:57
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The Tvs of Tomorrow: How RCA's Flat-Screen Dreams Led to the First Lcds
摘要： The Optimized Energy Degrading Optics (OEDO) beamline is an upgrade of the High-resolution beamline at the RI Beam Factory at RIKEN. Its purpose is to measure nuclear reactions induced by radioactive ions at 10–50 MeV/u. The main components of the OEDO beamline are two superconducting quadrupole triplet magnets and one radio-frequency deflector, which were recently installed. This setup produces slowed-down, well-focused radioactive-isotope beams by using a degree of freedom in the longitudinal phase space of the beam. This paper describes the OEDO beamline in detail, discusses the unique concept of its ion optics, and demonstrates its feasibility by conducting measurements with medium-mass radioactive-isotope beams.
关键词： RI Beam Factory,radioactive ions,superconducting quadrupole triplet magnets,OEDO,nuclear reactions,radio-frequency deflector
更新于2025-09-23 15:19:57
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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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Quantum Dots via rf Reflectometry
摘要： Silicon spin qubits show great promise as a scalable qubit platform for fault-tolerant quantum computing. However, fast high-fidelity readout of charge and spin states, which is required for quantum error correction, has remained elusive. Radio-frequency reflectometry enables rapid high-fidelity readout of GaAs spin qubits, but the large capacitances between accumulation gates and the underlying two-dimensional electron gas in accumulation-mode Si quantum-dot devices, as well as the relatively low two-dimensional electron gas mobilities, have made radio-frequency reflectometry challenging in these platforms. In this work, we implement radio-frequency reflectometry in a Si/Si-Ge quantum-dot device with overlapping gates by making minor device-level changes that eliminate these challenges. We demonstrate charge-state readout with a fidelity above 99.9% in an integration time of 300 ns. We measure the singlet and triplet states of a double quantum dot via both conventional Pauli spin blockade and a charge latching mechanism, and we achieve maximum fidelities of 82.9 and 99.0% in 2.08- and 1.6-μs integration times, respectively. We also use radio-frequency reflectometry to perform single-shot readout of single-spin states via spin-selective tunneling in microsecond-scale integration times.
关键词： quantum computing,Silicon spin qubits,spin-state readout,charge-state readout,radio-frequency reflectometry
更新于2025-09-23 15:19:57
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Demonstration of a Reconfigurable Entangled Radio-Frequency Photonic Sensor Network
摘要： Quantum metrology takes advantage of nonclassical resources such as entanglement to achieve a sensitivity level below the standard quantum limit. To date, almost all quantum-metrology demonstrations are restricted to improving the measurement performance at a single sensor, but a plethora of applications require multiple sensors that work jointly to tackle distributed sensing problems. Here, we propose and experimentally demonstrate a reconfigurable sensor network empowered by continuous-variable (CV) multipartite entanglement. Our experiment establishes a connection between the entanglement structure and the achievable quantum advantage in different distributed sensing problems. The demonstrated entangled sensor network is composed of three sensor nodes each equipped with an electro-optic transducer for the detection of radio-frequency (RF) signals. By properly tailoring the CV multipartite entangled states, the entangled sensor network can be reconfigured to maximize the quantum advantage in distributed RF sensing problems such as measuring the angle of arrival of an RF field. The rich physics of CV multipartite entanglement unveiled by our work would open a new avenue for distributed quantum sensing and would lead to applications in ultrasensitive positioning, navigation, and timing.
关键词： distributed sensing,entanglement,quantum metrology,electro-optic transducer,radio-frequency
更新于2025-09-23 15:19:57