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Visible light communication is seen as a crucial technology within optical wireless communication systems. The technology of vehicular visible light communication holds significant importance in the context of connected vehicles. This technology can serve as a supplementary solution to vehicular systems that are based on radio frequency. In this paper, the authors conduct an analysis of the performance of both line-of-sight and non-line-ofsight vehicle-to-vehicle visible light communication systems under the effect of artificial light source and weather conditions, including clear, hazy, and foggy weather. A practical vehicular laser diode, a street lamp, and an avalanche photodiode are used to design the proposed system model. Performance enhancement for the proposed system is achieved using an optical amplifier at the receiving end. An artificial light source of light-emitting diode Corn-type is used to represent an ambient artificial light source. Different metrics such as quality factor and bit error rate are used to assess the system performance of the non-lineof-sight-vehicular communication system. The proposed line-of-sight model achieves a data rate of 25 Gbps, supporting a distance of 80 m under clear sky and hazy atmospheric conditions. For foggy weather, an attainable link distance of 70 m is achieved. The achieved results emphasize the suitability of the suggested models for vehicular applications in real world environment. [ABSTRACT FROM AUTHOR]

This paper presents a new simplified procedure to design a fourth-order coupled resonator filter. This procedure does not require the calculation of complicated eigenvalues to develop the required coupling matrix. It starts with studying the effects of different coupling mechanisms on the performance of the overall filter structure. Then, these coupling mechanisms are combined to obtain the design of the required filter. This procedure may be more suitable for machine learning procedure to design coupled-resonator filters. The proposed method is used to design a substrate integrated waveguide (SIW) bandpass filter for sub-six GHz 5G applications. The designed SIW bandpass filter operates in the frequency range from 3.7 GHz to 3.98 GHz which covers the new C-band 5G network with a fractional bandwidth (FBW) of 28% and is centered at 3.84 GHz. This filter is fabricated and measured for verification. [ABSTRACT FROM AUTHOR]

This paper produces A simple compact band-notched dielectric resonator antenna used for ultra-wideband (UWB) applications. A rectangular dielectric resonator with rectangular air gab in the middle is used to achieve the optimum bandwidth and optimum gain for the proposed design. To eliminate any possible interference and overlapping, a new technique is presented to make a notch-band for the frequencies that are already used in the UWB such as the WLAN band (5.2-5.6GHz) by etching slots in the feedline. By varying the length of the slots, we can obtain many notch bands at various frequencies. The proposed antenna has a -10 dB impedance bandwidth of 87% from 3.2 GHz to 10.6 GHz. The proposed antenna is simulated by two simulation programs which are basically different to confirm the results; CST Studio suiteTM 2020 simulator based on the Finite-Difference Time-Domain (FDTD) method and HFSS 15 from Ansoft based on the Finite-Element Method (FEM). [ABSTRACT FROM AUTHOR]

Vehicular visible light communication is an emerging technology that allows wireless communication between vehicles or between vehicles and infrastructure. In this paper, a vehicular visible light communication system is designed using a non-return to zero on-off keying modulation scheme under the effect of different weather conditions such as clear, haze, and fog. The first model is a light emitting diode-based system and the second is a laser diode-based system. For both models, the influence of system parameters such as beam divergence, transceiver aperture diameters, and receiver responsivity is studied. The impact of the use of the trans-impedance amplifier is also investigated for both models. It was concluded that in the presence of the amplifier, output power of the light emitting diode and laser diode model are increased by 98.46 μW and 0.4719 W, respectively. The performance of the two proposed models is evaluated through bit error rate, quality factor, eye diagram, and output power to have some insightful results about the quality of service for the two proposed models. Under a specific weather condition, the performance of the system would be critical and other techniques should be applied. The maximum achievable link distance for the laser-based and light-emitting diode-based systems is 190 m at a data rate of 25 Gbps and 80 m at a data rate of 60 kbps, respectively, under the same system parameters and weather conditions. The obtained results provide a full idea about the availability of constructing our proposed model in a practical environment, showing a higher performance of the laser diode-based model than that of the light emitting diode-based model. [ABSTRACT FROM AUTHOR]

In this paper, a novel compact high-gain multi-layer dielectric resonator antenna for ultra-wideband applications is designed and fabricated. The proposed antenna employs a new technique to make a notch-band for the frequencies within UWB. This technique helps avoid any interference for bands like WLAN and X-band for satellite applications. In this design, several notch bands can get at different frequencies by changing the length of slots. The operating bandwidth of this antenna is between 4.8 GHz and 11.31 GHz with 10 dB return loss and maximum gain of 6 dBi. Finally, the proposed antenna is fabricated and measured to validate the simulation results. The simulation results are obtained by two different simulators; CST Studio suiteTM 2020 and HFSS 15 to ensure the validity of the design results before fabrication. The fabricated antenna is measured using Agilent R&S Z67 VNA. There is a good agreement between the simulation and experimental results. [ABSTRACT FROM AUTHOR]

In this paper, an optical modulator design based on a silicon-on-calcium fluoride platform with a layer of Vanadium dioxide (VO2) is proposed. The VO2 as a phase changing material is used to control the modulation process, making use of the phase transition of the VO2 material between dielectric and metallic states. The modal properties of the proposed optical modulator are studied and analyzed using the well-known full vectorial finite element method. Whereas, the light propagation is studied using the 3D finite difference time domain method. The suggested device offers a number of advantages such as low insertion loss of 0.431 dB/µm and high extinction ratio of 14.99 dB/µm at a wavelength of 3.95 µm and device length LD of 2 µm. To the best of the authors' knowledge, this is the first time to present an infrared optical modulator based on silicon-on-calcium fluoride platform. [ABSTRACT FROM AUTHOR]

A 6-element MIMO antenna system is introduced in this paper for N77, N78, and N79 (5G) communication bands. The proposed antenna element is composed of a four-section coupled line folded antenna. The performance of this antenna element is improved by using a partial ground plane combined with the DGS between the different elements of the MIMO antenna. The separated single antenna in this case has a reflection coefficient less than -10 dB over the frequency band from 3GHz to 5GHz. For the complete MIMO configuration, the reflection coefficient is less than -7dB over the same frequency band for all the antenna elements. On the other hand, the isolation between antenna elements in the MIMO configuration is greater than 15 dB. The values of the MIMO parameters are calculated. These parameters include the Envelope Correlation Coefficient between the different elements (ECC), Diversity gain (DG), Total Active Reflection Coefficient (TARC), Channel Capacity Loss (CCL), and Mean Effective Gain (MEG). Good results are obtained for the MIMO parameters where ECC < 0.006, DG = 10, TARC < -7, CLL < 0.6, and -3 < MEG < -8. These performance parameters of the proposed MIMO system indicate that this antenna is suitable for 5G applications. The effect of the human hand on the S-parameter is also investigated. The proposed antenna is fabricated and measured to verify the simulation results. [ABSTRACT FROM AUTHOR]

An effective multiport measurement system for the characterization of N-port nonlinear microwave devices is proposed. The proposed measurement system has the capability of measuring the S-parameters of linear microwave circuits and the amplitude-modulation-to-amplitude-modulation (AM/AM) and amplitude-modulation-to-phase-modulation (AM/PM) conversions for fundamental and harmonic frequencies for nonlinear microwave devices on single-step measurement without any need for reconnection or change in the calibration technique or measurement setup. It is found suitable that the proposed system can accurately quantify the impact of crosstalk on the performance of multibranch amplifiers and multiport nonlinear microwave systems in terms of power efficiency and signal distortion. [ABSTRACT FROM AUTHOR]