The uniform geometrical theory of diffraction (UTD) calculating edge diffraction, creeping diffraction, and reflection, has been widely used to predict the shadowing problems for the beyond 5th generation. The limitation of the previous work, which only discussed the relationship between edge diffraction and reflection in the lit region, has motivated the analysis of the difference between creeping diffraction and edge diffraction in the shadowed region. In this paper, as the difference between creeping diffraction and edge diffraction from a dielectric circular cylinder and an absorber screen, respectively, a novel additional term is derived based on the UTD in the shadowed region. In addition, a uniform additional term using the Fock-type integral is proposed to unify the formulations in the lit and shadowed regions. The proposed uniform additional term is validated by the UTD and exact solutions of a dielectric circular cylinder at millimeter-wave or sub-terahertz bands. From the discussion of the results, the proposal can not only unify the formulations in the lit and shadowed regions but also eliminate the fictitious interference. Through the proposal, we can separate the contribution of the shadowed Fresnel zone number (FZ) and boundary conditions (i.e., the surface impedance and polarization). The frequency characteristics of the shadowed FZ and boundary conditions are analyzed and simulated near a shadow boundary at a high frequency (10 GHz-100 GHz). The results imply that there is almost no dependency (less than 1 dB) on boundary conditions in the lit region while there are few dependencies (more than 1 dB) on boundary conditions in the shadowed region. This work attempts to unify three different propagation mechanisms, i.e., reflection, edge diffraction, and creeping diffraction, by using one formula.
2. Andersen, J. B., "UTD multiple-edge transition zone diffraction," IEEE Trans. Antennas Propag., Vol. 45, No. 7, 1093-1097, Jul. 1997.
doi:10.1109/8.596898
3. Pathak, P. H., W. Burnside, and R. Marhefka, "A uniform GTD analysis of the diffraction of electromagnetic waves by a smooth convex surface," IEEE Trans. Antennas Propag., Vol. 26, No. 5, 631-642, Sep. 1980.
doi:10.1109/TAP.1980.1142396
4. Pathak, P. H., "An asymptotic analysis of the scattering of plane waves by a smooth convex cylinder," Radio Science, Vol. 14, No. 3, 419-435, Jun. 1979.
doi:10.1029/RS014i003p00419
5. Pearson, L., "A scheme for automatic computation of Fock-type integrals," IEEE Trans. Antennas Propag., Vol. 35, No. 10, 1111-1118, Oct. 1987.
doi:10.1109/TAP.1987.1143985
6. Freund, D. E., N. E. Woods, H. Ku, and R. S. Awadallah, "Forward radar propagation over a rough sea surface: A numerical assessment of the Miller-brown approximation using a horizontally polarized 3-GHz line source," IEEE Trans. Antennas Propag., Vol. 54, No. 4, 1292-1304, Apr. 2006.
doi:10.1109/TAP.2006.872669
7. Dockery, G. D., R. S. Awadallah, D. E. Freund, J. Z. Gehman, and M. H. Newkirk, "An overview of recent advances for the TEMPER radar propagation model," 2007 IEEE Radar Conf., 896-905, 2007.
doi:10.1109/RADAR.2007.374338
8. Glaser, J. I., "Bistatic RCS of complex objects near forward scatter," IEEE Trans. Aerosp. Electron. Syst., Vol. 21, No. 1, 70-78, Jan. 1985.
doi:10.1109/TAES.1985.310540
9. Andrews, J. G., S. Buzzi, W. Choi, S. V. Hanly, A. Lozano, A. C. K. Soong, and J. C. Zhang, "What will 5G be?," IEEE J. Sel. Areas Commun., Vol. 32, No. 6, 1065-1082, Jun. 2014.
doi:10.1109/JSAC.2014.2328098
10. Rangan, S., T. S. Rappaport, and E. Erkip, "Millimeter-wave cellular wireless networks: Potentials and challenges," Proc. IEEE, Vol. 102, No. 3, 366-385, Mar. 2014.
doi:10.1109/JPROC.2014.2299397
11. Dore, J. B., Y. Corre, S. Bicais, J. Palicot, E. Faussurier, D. Ktenas, and F. Bader, "Above -90 GHz spectrum and single-carrier waveform as enablers for efficient Tbit/s wireless communications," 2018 25th Inter. Conf. Telecom. (ICT), 274-278, Saint-Malo, France, 2018.
12. MacCartney, G. R., S. Deng, S. Sun, and T. S. Rappaport, "Millimeter-wave human blockage at 73 GHz with a simple double knife-edge diffraction model and extension for directional antennas," 2016 IEEE 84th Vehi. Tech. Conf. (VTC-Fall), 1-6, Montreal, QC, Canada, 2016.
13. Sun, S., T. S. Rappaport, R. W. Heath, A. Nix, and S. Rangan, "MIMO for millimeter-wave wireless communications: Beamforming, spatial multiplexing, or both?," IEEE Commun. Mag., Vol. 52, No. 12, 110-121, Dec. 2014.
doi:10.1109/MCOM.2014.6979962
14. Sun, S., G. R. MacCartney, M. K. Samimi, and T. S. Rappaport, "Synthesizing omnidirectional antenna patterns, received power and path loss from directional antennas for 5G millimeter-wave communications," Proc. IEEE Global Commun. Conf. (GLOBECOM), 3948-3953, San Diego, CA, USA, Dec. 2015.
15. Balanis, C. A., Advanced Engineering Electromagnetics, Wiley, Hoboken, New Jersey, USA, 1989.
16. Clemmow, P. C., "Some extension to the method of integration by steepest descent," Q. J. Mech., Appl. Math. III, 241-256, 1950.
doi:10.1093/qjmam/3.2.241
17. Osipov, A. V. and S. A. Tretyakov, Modern Electromagnetic Scattering Theory with Applications, 274-277, Hoboken, New Jersey, USA: Wiley, 2013.
18. Keller, J. B., "Geometric theory of diffraction," J. Opt. Soc. Am., Vol. 52, No. 2, 116-130, 1962.
doi:10.1364/JOSA.52.000116
19. Du, X., K. Saito, J. Takada, and P. Hanpinitsak, "A novel mirror Kirchhoff approximation method for predicting the shadowing effect by a metal cuboid," Progress In Electromagnetics Research M, Vol. 104, No. 18, 199-212, Sep. 2021.
doi:10.2528/PIERM21041306
20. Du, X. and J. Takada, "Mirror Kirchhoff approximation for predicting shadowing effect by a PEC convex cylinder," 2021 Appl. Computa. Electromagn. Soci., Hamilton, Canada, Aug. 2021.
21. Du, X. and J. Takada, "Low computational cost mirror Kirchhoff approximation for predicting shadowing effect," IEEE Access, Vol. 10, 23829-23841, Feb. 2022.
doi:10.1109/ACCESS.2022.3155547
22. Du, X. and J. Takada, "Design of parameters of fast Fourier transform for three-dimensional split step parabolic equations and mirror Kirchhoff approximation," IEEE Access, Vol. 11, 44964-44976, May 2023.
doi:10.1109/ACCESS.2023.3273783
23. Basdemir, H. D., "Nonuniform currents flowing on a perfectly conducting cylinder," 2011 XXXth URSI General Assembly and Scienti c Symposium, 1-4, Istanbul, Turkey, 2011.
24. Basdemir, H. D., "Fringe waves on an impedance cylinder," Optik, Vol. 124, No. 21, 4999-5002, 2013.
doi:10.1016/j.ijleo.2013.03.089
25. Qi, Y., B. Currie, W. Wang, P. Y. Chung, C. Wu, and J. Litva, "Measurement and simulation of radio wave propagation in two indoor environments," Proc. 6th Inter. Symp. Pers., 1171-1174, Toronto, Ontario, Canada, 1995.
26. Jacob, M., S. Priebe, A. Maltsev, A. Lomayev, V. Erceg, and T. Kurner, "A ray tracing based stochastic human blockage model for the IEEE 802.11ad 60 GHz channel model," Proc. 5th Euro. Conf. Antennas Propag. (EUCAP), 3084-3088, Rome, Italy, 2011.
27. Villanese, F., N. E. Evans, and W. G. Scanlon, "Pedestrian-induced fading for indoor channels at 2.45, 5.7 and 62 GHz," 2000 IEEE 52nd Vehi. Tech. Conf. (VTC-Fall), 43-48, Boston, MA, USA, 2000.
28. Fakharzadeh, M., J. Ahmadi-Shokouh, B. Biglarbegian, M. R. Nezhad-Ahmadi, and S. Safavi-Naeini, "The effect of the human body on indoor radio wave propagation at 57-64 GHz," 2009 IEEE Antennas Propag. Soc. Inter. Symp., 1-4, North Charleston, SC, USA, 2009.
29. Duarte Carvalho de Queiroz, A. and L. C. Trintinalia, "An analysis of human body shadowing models for ray-tracing radio channel characterization," 2015 SBMO/IEEE MTT-S Inter. Microwave Optoelectron. Conf. (IMOC), 1-5, Porto de Galinhas, Brazil, 2015.
30. Tang, C., "Back scattering from dielectric-coated in nite cylindrical obstacles," J. Appl. Phys., Vol. 28, No. 5, 628-633, 1957.
doi:10.1063/1.1722815
31. Jacob, M., S. Priebe, T. Kurner, M. Peter, M. Wisotzki, R. Felbecker, and W. Keusgen, "Fundamental analyses of 60 GHz human blockage," Proc. 7th Euro. Conf. Antennas Propag. (EuCAP), 117-121, Gothenburg, Sweden, 2013.
32. Du, X. and J. Takada, "Structure of the eld behind a dielectric circular cylinder in the lit side of the transition region," Progress In Electromagnetics Research M, Vol. 116, No. 9, 103-118, Apr. 2023.
doi:10.2528/PIERM23022307
33. U mtsev, P. Y., Fundamentals of the Physical Theory of Diffraction, 1-48, Wiley, Hoboken, New Jersey, 2013.
34. U mtsev, P. Y., "New insight into the classical Macdonald physical optics approximation," IEEE Trans. Antennas Propag., Vol. 50, No. 3, 11-20, Jun. 2008.
doi:10.1109/MAP.2008.4563560
35. Wu, T., T. S. Rappaport, and C. M. Collins, "The human body and millimeter-wave wireless communication systems: interactions and implications," 2015 IEEE Inter. Conf. Communi. (ICC), London, UK, 2015.
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