- 标题
- 摘要
- 关键词
- 实验方案
- 产品
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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) - Solution-processed ultrathin SnO <sub/>2</sub> passivation of Absorber/Buffer Heterointerface and Grain Boundaries for High Efficiency Kesterite Cu <sub/>2</sub> ZnSnS <sub/>4</sub> Solar Cells
摘要： InP-based high electron mobility transistors (InP-HEMTs) and graphene-channel FETs (G-FETs) are experimentally examined as photonic frequency converters for future broadband optical and wireless communication systems. Optoelectronic properties and three-terminal functionalities of the InP-HEMTs and G-FETs are exploited to perform single-chip photonic double-mixing operation over the 120 GHz wireless communication band. A 10 Gbit/s-class data signal on a 112.5 GHz carrier is mixed down to a 25 GHz IF band with an 87.5 GHz LO signal that is simultaneously self-generated from an optically injected photomixed beat note. The results suggest that the intrinsic channel of the G-FET can achieve a speed performance that is superior to that of an InP-HEMT having an equivalent device feature size. The reduction of the extrinsic parasitic resistances and the implementation of an efficient photo-absorption structure in the G-FET may allow a millimeter-wave and sub-THz photonic frequency conversion with a sufficiently high conversion gain for practical purposes.
关键词： millimeter wave photonics,radio access networks,graphene,FETs,HEMTs,InP,millimeter wave communication,frequency conversion
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) - Numerical modeling and experimental realization of wide bandgap ZnTe-based solar cells for semi-transparent PV application
摘要： InP-based high electron mobility transistors (InP-HEMTs) and graphene-channel FETs (G-FETs) are experimentally examined as photonic frequency converters for future broadband optical and wireless communication systems. Optoelectronic properties and three-terminal functionalities of the InP-HEMTs and G-FETs are exploited to perform single-chip photonic double-mixing operation over the 120 GHz wireless communication band. A 10 Gbit/s-class data signal on a 112.5 GHz carrier is mixed down to a 25 GHz IF band with an 87.5 GHz LO signal that is simultaneously self-generated from an optically injected photomixed beat note. The results suggest that the intrinsic channel of the G-FET can achieve a speed performance that is superior to that of an InP-HEMT having an equivalent device feature size. The reduction of the extrinsic parasitic resistances and the implementation of an efficient photo-absorption structure in the G-FET may allow a millimeter-wave and sub-THz photonic frequency conversion with a sufficiently high conversion gain for practical purposes.
关键词： millimeter wave photonics,radio access networks,graphene,FETs,HEMTs,InP,millimeter wave communication,frequency conversion
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) - The Electrochemical Reactions in Crystalline Silicon Solar Modules
摘要： Millimeter-wave (mmWave) communication operated in frequency bands between 30 and 300 GHz has attracted extensive attention due to the potential ability of offering orders of magnitude greater bandwidths combined with further gains via beamforming and spatial multiplexing from multi-element antenna arrays. mmwave system may exploit the hybrid analog and digital precoding to achieve simultaneously the diversity, array and multiplexing gain with a lower cost of implementation. Motivated by this, in this paper, we investigate the design of hybrid precoder and combiner with sub-connected architecture, where each radio frequency chain is connected to only a subset of base station antennas from the perspective of energy efficient transmission. The problem of interest is a non-convex and NP-hard problem that is difficult to solve directly. In order to address it, we resort to design a two-layer optimization method to solve the problem of interest by exploiting jointly the interference alignment and fractional programming. First, the analog precoder and combiner are optimized via the alternating-direction optimization method where the phase shifter can be easily adjusted with an analytical structure. Then, we optimize the digital precoder and combiner based on an effective multiple-input multiple-output channel coefficient. The convergence of the proposed algorithms is proved using the monotonic boundary theorem and fractional programming theory. Extensive simulation results are given to validate the effectiveness of the presented method and to evaluate the energy efficiency performance under various system configurations.
关键词： Millimeter-wave communication,energy efficiency,interference alignment,analog precoding and combining,multiple-input multiple-output (MIMO) system
更新于2025-09-19 17:13:59
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[IEEE 2019 International Conference on Microwave and Millimeter Wave Technology (ICMMT) - Guangzhou, China (2019.5.19-2019.5.22)] 2019 International Conference on Microwave and Millimeter Wave Technology (ICMMT) - Design of a high outband rejection cross-coupled SIW filter for millimeter wave communications
摘要： In this paper, we demonstrate ultra-fast millimeter wave beam steering with settling times below 50 ps. A phased array antenna with two elements is employed to realize beam steering. The phased array feeder is implemented with a recently introduced time delay line that provides, at the same time, an ultra-fast tunability, broadband operation, and continuous tuning. Our implementation is used to perform symbol-by-symbol steering. In our demonstration, the beam direction is switched between two sequentially transmitted symbols toward two receivers placed 30° apart. We show the successful symbol-by-symbol steering for data streams as fast as 10 GBd. The suggested scheme shows that the ultra-fast beam steering is becoming practical and might ultimately enable novel high bit-rate multiple access schemes.
关键词： Ultra-fast beam steering,radio access network,microwave photonics,millimeter wave communication
更新于2025-09-16 10:30:52
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[IEEE 2018 48th European Microwave Conference (EuMC) - Madrid (2018.9.23-2018.9.27)] 2018 48th European Microwave Conference (EuMC) - Temperature Dependence of Bandpass Filters Built of Silica-Based Post-Wall Waveguide for Millimeter-Wave Applications
摘要： Temperature dependence is shown of fifth-order Chebyshev bandpass filters (BPFs) built of silica-based post-wall waveguide for millimeter-wave applications. The measured frequency drift of the three BPFs with the center frequencies of 59 GHz, 73 GHz and 84 GHz were 10.12 ppm/?C, 9.56 ppm/?C and 11.91 ppm/?C over the temperature range of 30?C to 90?C, respectively. It is confirmed that the stability of the silica-based BPFs is superior to commercial-waveguide BPFs.
关键词： Resonator filters,Millimeter wave communication,Millimeter wave devices
更新于2025-09-12 10:27:22
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Uplink Channel Estimation and Data Transmission in Millimeter-Wave CRAN with Lens Antenna Arrays
摘要： Millimeter-wave (mmWave) communication and network densification hold great promise for achieving high-rate communication in next-generation wireless networks. Cloud radio access network (CRAN), in which low-complexity remote radio heads (RRHs) coordinated by a central unit (CU) are deployed to serve users in a distributed manner, is a cost-effective solution to achieve network densification. However, when operating over a large bandwidth in the mmWave frequencies, the digital fronthaul links in a CRAN would be easily saturated by the large amount of sampled and quantized signals to be transferred between RRHs and the CU. To tackle this challenge, we propose in this paper a new architecture for mmWave-based CRAN with advanced lens antenna arrays at the RRHs. Due to the energy focusing property, lens antenna arrays are effective in exploiting the angular sparsity of mmWave channels, and thus help in substantially reducing the fronthaul rate and simplifying the signal processing at the multi-antenna RRHs and the CU, even when the channels are frequency-selective. We consider the uplink transmission in a mmWave CRAN with lens antenna arrays and propose a low-complexity quantization bit allocation scheme for multiple antennas at each RRH to meet the given fronthaul rate constraint. Further, we propose a channel estimation technique that exploits the energy focusing property of the lens array and can be implemented at the CU with low complexity. Finally, we compare the proposed mmWave CRAN using lens antenna arrays with a conventional CRAN using uniform planar arrays at the RRHs, and show that the proposed design achieves significant throughput gains, yet with much lower complexity.
关键词： lens antenna array,antenna selection,fronthaul constraint,millimeter-wave communication,quantization bit allocation,Cloud radio access network,channel estimation
更新于2025-09-10 09:29:36
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Robust Hybrid Transceiver Design for AF Relaying in Millimeter Wave Systems Under Imperfect CSI
摘要： In this paper, we present a robust hybrid transceiver design for millimeter-wave communication systems operating in amplify-and-forward multiple-input multiple-output relay channels. Unlike most of current works that assume the perfect or partial channel state information (CSI) at the transceivers in the design, the CSI uncertainty is taken into consideration to design a robust transceiver. To achieve that end, the average received signal-to-noise ratio (SNR) is adopted as the objective function. To produce a tractable expression, an accurate approximation of the average received SNR is derived and used as the design criterion. An alternating maximization algorithm is proposed to optimize the design criterion, in which an orthogonal matching pursuit-based algorithm is utilized to design the transceiver at the relay. Simulations show that the algorithm takes a few iterations to produce converged transceivers for the source, relay, and destination nodes. Numerical results demonstrate the substantial performance gains of the proposed scheme, compared with the existing non-robust designs.
关键词： MIMO,cooperative communication,Millimeter wave communication
更新于2025-09-09 09:28:46
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Comparison of Optical Single Sideband Techniques for THz-over-fiber Systems
摘要： The use of single sideband (SSB) signals and envelope detection is a promising approach to enable the use of economic free-running lasers in photonic THz communications. To combat the signal-signal beat interference (SSBI) associated with envelope detection, broad guard bands (GBs) may be used given the large unregulated spectrum available at THz frequencies (100 GHz – 10 THz). In this scenario, the conventional way of generating SSB signals through a digital SSB filter (here referred to as the CSSB scheme) would require quite high analog digital-to-analog converter (DAC) bandwidths. Digital virtual SSB (DVSSB) and analog virtual SSB (AVSSB) have been proposed in direct-detection optical systems for relaxing the DAC bandwidth requirements. In this paper, we compare the three techniques through simulations and implement them, for the first time, in a THz-over-fiber (ToF) system operating at 250 GHz. For the transmission experiments we employ 5 GBd 16-QAM signals with three different GBs (5.5 GHz, 4.75 GHz and 3.5 GHz). The simulations show that the best performance is obtained with the AVSSB technique, while the worst is obtained with the DVSSB scheme, where the quality of the generated sideband degrades with carrier-to-sideband power ratio. In the experimental transmissions, where receiver noise was the main source of noise, similar behavior was found between the three techniques. At the 3.5 GHz GB, however, the DVSSB exhibited a penalty of 1 dB with respect to the other two. This is likely to be due to nonlinear distortions caused by the increase in the virtual tone power.
关键词： microwave photonics,Broadband communication,semiconductor lasers,photonic integrated circuits,digital signal processing,envelope detectors,optical mixing,millimeter wave communication
更新于2025-09-04 15:30:14
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[IEEE 2018 13th European Microwave Integrated Circuits Conference (EuMIC) - Madrid, Spain (2018.9.23-2018.9.25)] 2018 13th European Microwave Integrated Circuits Conference (EuMIC) - Ultra-Broadband Frequency Multiplier MMICs for Communication and Radar Applications
摘要： Two H-band frequency multiplier MMICs, a frequency doubler and tripler, are presented. Both circuits were characterized over a frequency range of 235 - 285 GHz. The 3-dB bandwidth of both chips exceeds the measurement range of 50 GHz. Without any post-ampli?cation the multiplier-by-3 achieves an average output power of -6 dBm at an input power of 6 dBm. The multiplier-by-two generates -3.6 dBm average at an input power of 5 dBm. Both MMICs were realized in a 35 nm gate-length InGaAs-based metamorphic HEMT technology. A comparison of simulation and measurement was conducted and shows a very good correspondence.
关键词： S-MMIC,Frequency conversion,Millimeter wave communication
更新于2025-09-04 15:30:14