Transactions on Antennas and Propagation
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| H , V and M The IPD of each radome are set to have a uniform color representation in order to facilitate the comparison of them. ab) c) (d) Fig. 9 IPD of optimum CTR and incident angle distribution under 6° scan angle. a) Parallel polarization - H . (b) Perpendicular polarization - V . (c) Co-polarization - M . (d) Incident angle distribution. ab) c) (d) Fig. 10 IPD of inhomogeneous radome and polarization angle distribution under 6° scan angle. (a) Parallel polarization - H . (b) Perpendicular polarization- V . (c) Co-polarization - M . (d) Polarization angle distribution. ab) c) Fig. 11 IPD of VTR. (a) Parallel polarization - H . (b) Perpendicular polarization- V . (c) Co-polarization - M T ABLE I IPD VARIATION INTERVAL UNDER 6° SCAN ANGLE INTERVAL UNIT RAD ) Inhomo. radome CTR VTR Interval of H [0.227, 0.313] [2.279, 2.586] [2.172, Interval of V [0.318, 0.500] [2.367, 2.629] [2.103, Interval of M [0.227, 0.463] [2.281, 2.599] [2.160, Interval length of H 0.086 0.307 0.339 Interval length of V 0.182 0.262 0.452 Interval length of M 0.236 0.318 0.351 Overlap ratio -0.02 0.63 0.75 Range ratio 0.47 0.85 0.75 jg -0.03 1.17 1.31 ab) (c) Fig. 12 Interval of H , V and M under 6° scan angle corresponding to Table Ia) Inhomogeneous radome. (b) CTR. (c) VTR. It has been pointed out in Section II (B) that T H and T V depend on the radome thickness, permittivity, incident angle and frequency, of which the permittivity and frequency are always constant for the radome in this work. For inhomogeneous ra- dome and CTR, as thickness is also constant, the IPD distribution of T H and T V , that is, H and V , depend solely on the incident angle distribution. In Fig. 9, H and V both have a similar distribution as the incident angle, whereas in Fig. 10, H has nearly a constant distribution with the value close to X (c) 2016 IEEE. Personal use is permitted, but republication/redistribution requires IEEE permission. See http://www.ieee.org/publications_standards/publications/rights/index.html for more information. This article has been accepted for publication in a future issue of this journal, but has not been fully edited. Content may change prior to final publication. Citation information DOI TAP, IEEE Transactions on Antennas and Propagation > REPLACE THIS LINE WITH YOUR PAPER IDENTIFICATION NUMBER (DOUBLE-CLICK HERETO EDIT) < 8 the minimum (corresponds to blue color) while V constant with the value close to the maximum (corresponds to red color. Keep in mind that this is just due to the fact that H and V are compelled to be plotted in the same value range, and otherwise, H and V would have almost exactly the same distribution as the incident angle. Even so, if checked carefully, a similarity between H , V and the incident angle can still be identified to some degree. Moreover, irrespective of inhomo- geneous radome, CTR or VTR, perpendicular polarization tends to cause a larger IPD than parallel polarization does, that is, V is slightly larger than H , as shown in Fig. 9-11 and Table I. In Fig. 9, H and V have a similar distribution as the incident angle, which, as they are shown in the same value range, means that they have similar distribution characteristics and similar value (i.e., small IPD difference between parallel and perpendicular polarization. Therefore, from (3), M will also have a similar distribution as the incident angle, and is not much relevant to the polarization angle distribution. As mentioned in Section II (A, when polarization angle is close to 0°/90°, Download 1 Mb. Share with your friends:
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