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- 摘要
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- 实验方案
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[IEEE 2018 21st Saudi Computer Society National Computer Conference (NCC) - Riyadh, Saudi Arabia (2018.4.25-2018.4.26)] 2018 21st Saudi Computer Society National Computer Conference (NCC) - Millimeter Wave Switching in Radio over Fiber Networks using Semiconductor Optical Amplifier (SOA)
摘要： 5G wireless communication systems promise efficient spectrum utilization, advanced modulation and access techniques, and high data rate. To obtain these requirements, millimeter wave (MMW) signals and subsystems are the most suitable to be used. The Modules and devices, proposed for these networks, are intended to use the efficient capabilities of photonic technologies. In this paper, a photonics-based millimeter wave switch, for orthogonal frequency division multiplexing (OFDM) signals, is proposed by exploiting the nonlinear effects in semiconductor optical amplifiers (SOAs). This includes four wave mixing (FWM), self-phase modulation (SPM) and cross-gain modulation (XGM). A 10 Gbps/16QAM-OFDM signal carried over 30 GHz MMW carrier is considered for signal switching. Moreover, we studied the up- and down- wavelength conversion schemes, in terms of probe and pump signal’s power. Furthermore, we investigate the effects of SOA’s injection current and wavelength spacing between the two injected beams that enable optical single sideband (OSSB) generation and switching. Simulation results show possibility of transmitting and switching OFDM signal with 1×10-3 and 13 % rms symbol error rate (SER) and error vector magnitude (EVM), at -22 dBm received power. The simulation is carried out using Virtual Photonic Integrated (VPI) software.
关键词： optical single side band (OSSB),orthogonal frequency division multiplexing (OFDM),millimeter waves (MMW),semiconductor optical amplifier (SOA),wavelength conversion,5G
更新于2025-09-23 15:23:52
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Tissue-mimicking materials for breast phantoms up to 50 GHz
摘要： Millimeter (mm)-wave imaging has been recently proposed as a new technique for breast cancer detection, based on the significant dielectric contrast between healthy and tumor tissues. Here we propose a procedure to fabricate, electromagnetically characterize and preserve realistic breast tissue-mimicking phantoms for testing mm-wave imaging prototypes. Low-cost, non-toxic and easy-to-produce mixtures made of sunflower oil, water and gelatin were prepared and their dielectric properties were for the first time measured in the [0.5-50] GHz frequency range using a coaxial probe kit. Different oil and gelatin percentages were tested. An alternative recipe based on a waste-oil hardener was also proposed. Finally, water and sunflower oil were investigated as preservation media. The mixtures electromagnetic properties were in good agreement with those of human breast ex vivo samples. By changing the ingredient concentrations or using different solidifying agents it was possible to mimic different tissue types. Besides, we show that sunflower oil represents an effective preservation medium for the developed materials. The first breast phantom mimicking a tumor mass into healthy tissues up to 50 GHz was also successfully fabricated. Results demonstrated the potential of the designed recipes to mimic breast tissues with different biological characteristics.
关键词： microwave imaging,breast phantoms,breast cancer,dielectric properties,millimeter waves,cancer screening
更新于2025-09-23 15:22:29
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[IEEE 2018 International Conference on Wireless Communications, Signal Processing and Networking (WiSPNET) - Chennai (2018.3.22-2018.3.24)] 2018 International Conference on Wireless Communications, Signal Processing and Networking (WiSPNET) - An Efficient Photonic-based Millimeter Wavelength Switching Techniques Towards 5G
摘要： Millimeter Waves (MMWs) operating at 30–300 GHz band, is very encouraging to the next-generation 5G wireless communication systems, supporting data rates of multiple Gbps per user. By using the Four Wave Mixing (FWM), Self-Phase Modulation (SPM) and Cross Phase Modulation (XPM) effects in the Semiconductor Optical Amplifier (SOA) and Erbium Doped Fiber Amplifier (EDFA), the photonic millimeter switching is realized. These effects can reduce the switching crosstalk since the Optical Single Sideband (OSSB) signal occupies the least optical bandwidth. The best operating conditions improve the Sideband Suppression Ratio (SSR) and at the same time reduce the intensity of unintended sideband signal. This leads to a dispersion-free transmission in the optical fiber and improves the data rate as required in 5G communication. In this paper, the wavelength switching of a 9 Gbps QPSK signal carried on the 30 GHz over a spacing of 1.6 nm as a function of probe wavelength of 1548.515 nm and pump wavelength of 1550.115 nm is achieved.
关键词： Millimeter Waves,Four Wave Mixing,Self Phase Modulation,Cross Phase Modulation,Erbium Doped Fiber Amplifier
更新于2025-09-23 15:22:29
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Spectroscopic diagnostics of continuous and transient microplasma formed in a millimeter wave photonic crystal
摘要： We present spectroscopic measurements of a microplasma formed within a photonic crystal (PhC) at argon gas pressures up to 750 Torr. Continuous and pulsed millimeter waves (MMW) generate plasma at a vacancy defect within the crystal. Rotational gas temperatures of 300-1050 K and electron densities of 0.5-2×1020 m-3 are obtained from the CH rotational emission spectrum and from Stark broadening of the ???? atomic transition. Electron density is found to be weakly dependent on MMW power because the plasma expands within the defect volume at higher power. Pulsed MMWs slightly increase the peak electron density compared to continuous waves with the same peak power. With MMW pulses, a rapid decrease of wave transmission through the PhC is observed at the beginning of plasma formation. During plasma ignition two distinct plasmas are formed, one on the conducting wall of the PhC near the optical access port and a second within the center of the PhC defect. With longer periods between pulses, the weak wall plasma is observed to form before the principal plasma in the defect, which aids in initiating the main plasma.
关键词： photonic crystal,millimeter waves,electron density,spectroscopic diagnostics,microplasma,gas temperature
更新于2025-09-23 15:19:57
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QPSK detection using glow discharge detector and a photodiode for millimetera??wave and terahertz communication
摘要： The terahertz gap (0.1-10 THz) is an attractive frequency band for new applications. In wireless communication, it can serve as a high capacity link. The lack in use of that gap exists due to a lack of available commercial communications technology systems in that region. We have found that neon indicator lamps or glow discharge detectors (GDD) can be used as simple and very inexpensive detectors in that frequency gap. In modern modulation techniques, the signal phase should be recovered. This article is a proof of concept of detection of quadratic amplitude modulated millimeter-wave signals by a GDD and photodiode using a heterodyne detection method.
关键词： communication,terahertz,millimeter waves,glow discharge,heterodyne detection
更新于2025-09-19 17:13:59
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Characterization of Optical Fibers Directly Embedded on Metal using a Particle Spray based Method
摘要： The double corrugated waveguide (DCW), incorporating a row of metallic pillars on each side of the electron beam, is demonstrated as a promising slow-wave structure for millimeter wave, Ka-band, traveling wave tubes (TWTs). Different configurations, including novel bent couplers with tapered pillars, have been designed, realized, and validated by S-parameter measurements. The design and simulation of a DCW TWT demonstrated very good performance in the frequency band 32–37 GHz. The ease of fabrication and assembly make the DCW a suitable basis for a new generation of millimeter wave TWTs.
关键词： microfabrication,millimeter waves,slow-wave structures (SWSs),Double corrugated waveguide (DCW),traveling wave tubes (TWTs),satellite communications
更新于2025-09-19 17:13:59
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[IEEE 2018 48th European Microwave Conference (EuMC) - Madrid (2018.9.23-2018.9.27)] 2018 48th European Microwave Conference (EuMC) - Carbon Nanotube Layer Modeling for Computer Simulation of Optically Controlled Phase Shifters
摘要： We propose an approach for efficient modeling of thin carbon nanotube layers for full-wave device simulations without increasing the number of simulation mesh cells. A surface impedance, used in computer simulations, is calculated from the dielectric constant of the material. The dielectric constant is modeled by a Drude–Lorentz resonance, fitted to experimental results. The approach allowed to study the nanotube-induced losses and finite-size resonance effects in optically-controlled, dielectric rod waveguide-based phase shifters. The correctness of the model was verified both by the simulated and the measured S-parameters in the W-band.
关键词： numerical simulation,optically controlled phase shifter,surface impedance,millimeter waves,carbon nanotubes
更新于2025-09-16 10:30:52
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[IEEE 2019 XXIVth International Seminar/Workshop on Direct and Inverse Problems of Electromagnetic and Acoustic Wave Theory (DIPED) - Lviv, Ukraine (2019.9.12-2019.9.14)] 2019 XXIVth International Seminar/Workshop on Direct and Inverse Problems of Electromagnetic and Acoustic Wave Theory (DIPED) - Waveguide Millimeter Wave Measurement Cell with Minimum Reflection Coefficient for Complex Permittivity Determination of Bioactive Liquids
摘要： An original waveguide millimeter wave measurement cell for complex permittivity determination of bioactive high-loss liquids was studied numerically and experimentally. This measurement cell consisted of round metal waveguide, Teflon inserted and glass capillary with liquid under test inside. The main features of the measurement cell are as follows. Waveguide connections (matching elements) to input and output waveguides have minimum reflection coefficient. The capillary with the high loss liquids under test located not in the electromagnetic field maximum as usual, but at an angle to the wave propagation along the waveguide cell. The advantages of such capillary location were discussed in the paper. This waveguide millimeter wave measurement cell was compared with the symmetrical waveguide millimeter wave measurement cell for complex permittivity determination.
关键词： millimeter waves,reflection coefficient,Microwave resonator,complex permittivity,bioactive liquids,frequency spectrum,waveguide
更新于2025-09-16 10:30:52
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Error Tolerant Method of Dielectric Permittivity Determination Using a TE?? Mode in a Circular Waveguide at the W-Band
摘要： We propose a new method for the precise measurement of dielectric permittivity of ceramics and polymers at millimeter-wave frequencies that employs the TE01 mode of a circular waveguide. At higher frequencies, accurately measuring the dielectric permittivity of materials becomes extremely challenging by using the fundamental TE10 mode of a rectangular waveguide. As the frequency increases, the dimensions of the dielectric sample that has to be fit into the waveguide become very small. Therefore, small fabrication imperfections that produce air gaps between the sample and the wall of the waveguide result in significant errors during measurements. In contrast, the TE01 mode of the circular waveguide that does not have an electric field at the surface of the waveguide is insensitive to small imperfections during fabrication. We measured the dielectric permittivity in small samples of alumina (Al2O3), magnesium calcium titanate (MCT) ceramics, and Teflon placed in a circular waveguide. The results showed that the method was very robust with respect to manufacturing imperfections: when dimensions of the alumina and Teflon samples varied by as much as 10% and 20%, the differences in the computed dielectric permittivity of the alumina were only 1.26% and 3.06%, respectively, and those of Teflon were 1.98% and 2.12%. In addition, when the high-dielectric permittivity material MCT samples were deformed by 5% and 10%, the differences were just 0.04% and 0.14% each, respectively. We believe that this new proposed method is also applicable to even higher frequencies in the THz regime and at a very high relative dielectric permittivity of larger than 10.
关键词： millimeter waves,Ceramic materials,measurement,resonant-based method,dielectric permittivity,waveguide
更新于2025-09-12 10:27:22
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Design of Substrate Integrated Gap Waveguide and Their Transitions to Microstrip Line, for Millimeter-Wave Applications
摘要： This paper offers an approximate, but very convenient and accurate, manner to find the desired strip width for substrate integrated gap waveguide (SIGW) with a given characteristic impedance and the conductor and dielectric attenuation constants, without any complicated manual calculations or time-consuming full-wave simulation and optimization iterations. Moreover, the investigation of the transition between SIGW and microstrip lines will prove that an additional transition structure, such as a conventional microstrip taper, is not required any more at millimeter-wave frequencies for the desired transmission performance. This is a useful feature in circuit design and compactness. Both of the above works will be of great help to realize future feeding networks for SIGW antenna arrays or other types of cost-effective SIGW passive components at high frequencies. Two SIGW prototypes, working at Ka and V bands, are fabricated and offer experimental verifications, which present good agreement with the simulation results.
关键词： 5G,characteristic impedance,Gap waveguide,transition,attenuation constant,millimeter waves
更新于2025-09-11 14:15:04