Microwave Specific Attenuation by Oblate Spheroidal Raindrops: an Exact Analysis of TCS's in Terms of Spheroidal Wave Functions

Li, L. W.; Yeo, T. S.; Kooi, P. S.; Leong, M. S.

doi:10.2528/pier97080100

Cited by 7 publications

(7 citation statements)

References 13 publications

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“…Added to that, a signal wavelength ratio to raindrop size and the irregularity of raindrop shapes increase the complexity of estimating the SRA. The irregularity of rain drops combined with the temperature of rain further worsen the scattering and absorption of the propagated signal . Thus, all these parameters are, usually, lumped in a simplified model to estimate SRA, γ , expressed as

γ = k R^{α}

where k and α are regression parameters estimated empirically from site‐specific measurements, and R is the radius of raindrops.…”

Section: Calculation Of Rain Attenuationmentioning

confidence: 99%

Rain attenuation and worst month statistics verification and modeling for 5G radio link system at 26 GHz in Malaysia

Shayea

Nissirat

Nisirat

et al. 2019

Trans Emerging Tel Tech

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The explosive daily dependence on wireless communication services necessitates the research to establish ultrawideband communication systems with ultrahigh bit rate transmission capabilities. The advent of the fifth-generation (5G) microwave link transmitting at millimeter-wave (mm-wave) frequency band is a promising technology to accommodate the escalating demand for wireless services. In this frequency band, however, the behavior of the transmission channel and its climatic properties are a major concern. This is of particular importance in tropical regions where the climate is mainly rainy with large raindrop size and high rainfall rate that may interact destructively with the propagating signal and cause total attenuation for the signal. International Telecommunication Union (ITU) introduced a global rain attenuation model to characterize the effect of rain on the propagating signal at a wideband of frequencies. The validity of this model in tropical regions is still an open question for research. In this paper, real measurements are conducted at Universiti Teknologi Malaysia (UTM), Johor Bahru, Malaysia, to investigate the impact of rain on the propagation of mm-waves at 26 GHz over the microwave 5G radio link system. Rainfall rate and rain attenuation data sets are collected for one year at one sample per min sampling rate. Both data sets are used to estimate signal propagation conditions in comparison to the ITU model prediction. From the presented results, it is found that at 0.01% percentage of time and rainfall rate of about 120 mm/hr, the propagated signal would experience 26.2 dB losses per kilometer traveled. In addition, there is a significant deviation between the empirical estimation of the worst month parameters and the ITU worst month parameter prediction. Similarly, rainfall rate and rain attenuation estimated through the ITU model imposes a large deviation as compared with the measurements. Furthermore, more accurate empirical worst month parameters are proposed that yielded more accurate estimation of the worst month rainfall and rain attenuation predictions in comparison to the ITU model predictions. Trans Emerging Tel Tech. 2019;30:e3697. wileyonlinelibrary.com/journal/ett

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γ = k R^{α}

where k and α are regression parameters estimated empirically from site‐specific measurements, and R is the radius of raindrops.…”

Section: Calculation Of Rain Attenuationmentioning

confidence: 99%

Rain attenuation and worst month statistics verification and modeling for 5G radio link system at 26 GHz in Malaysia

Shayea

Nissirat

Nisirat

et al. 2019

Trans Emerging Tel Tech

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“…Equations (9) and (10) still can be used for this purpose; however, due to the different geometrical structure, the enclosed area and its surrounding contour segments' length are obtained by …”

Section: Fdtd Grid Singularitiesmentioning

confidence: 99%

“…Now, like all the previous cases, the analysis methods in the spheroidal domains can be used either for designing spheroidal devices (e.g. cavities, multilayer dielectric antennas, and conformal microwave devices and antennas) or computing the interaction of electromagnetic waves with spheroidal objects [8] [9]. In addition, both oblate and prolate spheroidal surfaces provide 360 degrees azimuth and elevation coverage by conformal arrays.…”

Section: Introductionmentioning

confidence: 98%

Spheroidal FDTD Method for Modeling 3-D Structures in Open and Closed Domains

Al-Hasson

Schoebel

2015

IEEE Trans. Antennas Propagat.

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A Finite Difference Time Domain (FDTD) method for analyzing spheroidal open and closed structures is introduced. Its mathematical equations are derived and discretized according to a designed geometrical model. The field's singularities at the domain's center and vertical axis are dealt with by deriving alternative field formulas. The method is then extended to open domains by deriving an absorbing boundary condition. The stability of the obtained model is determined by deriving its mathematical condition. Finally, the method is used to characterize spheroidal cavities and a conformal patch antenna. Index Terms-Finite Difference Time Domain, FDTD, spheroidal cavities, and spheroidal patch.

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“…Knowledge of the scattered fields is required in many areas, such as investigations of the scattering of light by small chemical and biological particles [2] and the scattering of microwaves by raindrops [7]. Quite a few methods have been used in the analysis of different scattering problems (more descriptions can be found in [3]).…”

Section: Introductionmentioning

confidence: 99%

“…The scattering of electromagnetic waves by dielectric objects has for a long time been a hot research topic [1][2][3][4][5][6][7][8]. Knowledge of the scattered fields is required in many areas, such as investigations of the scattering of light by small chemical and biological particles [2] and the scattering of microwaves by raindrops [7].…”

Section: Introductionmentioning

confidence: 99%

Scattering by an Arbitrarily Shaped Rotationally Uniaxial Anisotropic Object: Electromagnetic Fields and Dyadic Green's Fucntions

Liu

Leong

et al. 2000

PIER

Self Cite

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Abstract-The electromagnetic scattering by a three-dimensional arbitrarily shaped rotationally uniaxial anisotropic object is studied. Electromagnetic fields in a uniaxial medium are solved for first using the method of separation of variables, and then expressed in a very compact form by introducing the modified spherical vector wave functions. The equivalence theorem and the T-matrix method are applied in the analysis of the scattering problem. The scattered fields and the dyadic Green's functions both external and internal to the scatterer are derived in terms of spherical vector wave functions and matrix-form coefficients. Through making use of the dyadic Green's functions obtained, numerical results are provided for an incident field excited by an infinitesimal dipole. The scatterers are assumed to be prolate and oblate dielectric spheroids with the rotational z-axis. The angular scattering intensities in far-zone are plotted for all these cases. And some conclusions are also drawn eventually from numerical discussions.

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Microwave Specific Attenuation by Oblate Spheroidal Raindrops: an Exact Analysis of TCS's in Terms of Spheroidal Wave Functions

Cited by 7 publications

References 13 publications

Rain attenuation and worst month statistics verification and modeling for 5G radio link system at 26 GHz in Malaysia

Rain attenuation and worst month statistics verification and modeling for 5G radio link system at 26 GHz in Malaysia

Spheroidal FDTD Method for Modeling 3-D Structures in Open and Closed Domains

Scattering by an Arbitrarily Shaped Rotationally Uniaxial Anisotropic Object: Electromagnetic Fields and Dyadic Green's Fucntions

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