小型小区和设备到设备(D2D)通信将在下一代无线移动通信系统(IMT-2020或5G)的实现中发挥至关重要的作用。它们都涉及不到10 m高的发射器和接收器,从而导致更加复杂的城市环境。本文提出了一个框架,将诸如交通标志,交通信号灯等复合城市家具集成到光线追踪工具中。该框架从家具部件雷达横截面的理论建模和远场全波分析仿真的验证开始。然后,为了在小型单元或D2D场景中局部满足远场条件,将家具划分为小段,以便远场模型仍然适用。最后,分解后的家具在光线跟踪工具中实现,并通过实际场景中的测量进行验证。在此框架下,研究人员可以使用城市环境的更多基本要素来改进光线跟踪工具。最后但并非最不重要的一点是,本文提供了一个案例研究来演示该框架的实现,结果表明交通标志确实影响了车辆到车辆的通信,这是室外D2D系统最常出现的应用之一。
2021-03-21 09:12:59 640KB Device-to-device ray-tracing scattering small
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通过积分方程方法解决电磁(EM)问题取决于对与格林函数有关的奇异积分的准确评估。 在使用具有Rao-Wilton-Glisson(RWG)基函数的矩量法(MoM)来求解表面积分方程(SIE)时,标量Green函数上的梯度算子可以移到基本函数和测试函数上,从而得到积分核中的1 / R弱奇异点,其中R是观察点和源点之间的距离。 弱奇异积分可以使用众所周知的Duffy方法求值,但它需要进行两次数值积分。 在这项工作中,我们开发了一种通过使用局部极坐标系来评估奇异积分的新颖方法。 通过推导极坐标上积分的闭合形式表达式,该方法可以自动消除奇异性并将积分减小为一倍数值积分。 数值算例表明了该方法的有效性。
2021-03-02 21:05:32 782KB Electromagnetic scattering; integral equations;
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Nonlinear optical properties of stimulated Brillouin scattering (SBS) to signal detection in water are analyzed. With the threshold characteristics, SBS only occurs when the high power laser is focused in the SBS cell. When there is an object present in front of the focus, it leads to lower incident intensity and then SBS does not occur. The backward SBS signal depends on the focusing location. The nonlinear optical properties of SBS process in the focusing regime are analyzed theoretically. Wit
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We demonstrate a multiple wavelength Brillouin/erbium fiber laser in a linear cavity configuration. The laser cavity is made up of a fiber loop mirror on one end of the resonator and a virtual mirror generated from the distributed stimulated Brillouin scattering effect on the other end. Due to the weak reflectivity provided by the virtual mirror, self-lasing cavity modes are completely suppressed from the laser cavity. At Brillouin pump and 1480-nm pump powers of 2 and 130 mW, respectively, 11 c
2021-02-26 09:05:52 442KB 光纤激光 分布式布 140.3500 290.5900
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本文从级联网络关系推导了校准对称设备的微波测试夹具的一般解决方案,并通过三次测量揭示了校准对称设备的任意测试夹具的可能性和条件,该结果小于通过反射线(TRL)方法的测量时间。 测试夹具和嵌入式对称设备的散射参数可以通过测量直通线,直线和对称设备来确定。 此外,通过仿真和测量对该方法进行了分析和验证。 分析表明,所提出的方法适用于确定被测对称设备(DUT)的校准S参数。
2021-02-24 09:09:08 894KB Calibration; deembed; microwave; scattering
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We present the generation of the nanosecond cylindrical vector beams (CVBs) in a two-mode fiber (TMF) and its applications of stimulated Raman scattering. The nanosecond (1064 nm, 10 ns, 10 Hz) CVBs have been directly produced with mode conversion efficiency of ~18 dB (98.4%) via an acoustically ind
2021-02-21 19:10:00 1.48MB
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A spatial distribution of diffuse reflectance produced by obliquely incident light is not centered about the point of light entry. The value of shift in the center of diffuse reflectance is directly related to the absorption coefficient \mu_{a} and the effective attenuation coefficient \mu_{eff}. \m
2021-02-10 16:05:32 311KB 组织光学 漫反射 光学常数 皮肤组织
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Wideband Tunable Low Noise Microwave Generation Utilizing an Optoelectronic Oscillator Based on the Deamplification of Stimulated Brillouin Scattering
2021-02-07 16:03:26 266KB 研究论文
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Wideband tunable optoelectronic oscillator based on the deamplification of stimulated Brillouin scattering
2021-02-07 16:03:24 1.25MB 研究论文
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