LIST OF FIGURESFigurePage2.1 Geometry of pyramidal a <strong>horn</strong> <strong>antenna</strong>. 62.2 Stepped-waveguide model of tapered region of <strong>horn</strong> <strong>antenna</strong>. 62.3 Radiating aperture of a <strong>horn</strong> <strong>antenna</strong> 72.4 Step discontinuity between i-th and i + 1-th waveguide sections. 82.5 Scattering matrix representation of cascaded discontinuities 172.6 Generalized reflection matrix representation of an aperture. 182.7 (a) Original problem (b) Equivalent problem (valid only in waveguide section)(c) Equivalent problem (valid only in half space section ). 192.8 Rooftop expansion function for MX and MY 233.1 Stepped-<strong>horn</strong> <strong>antenna</strong> with variable <strong>dielectric</strong> loading for excitation of TE30mode at the aperture with 1/3 amplitude ratio of TE10 mode 363.2 as and aA width of H -plane step for TE30 mode amplitude in the ratio 1/3 tothe TE10 mode excitation. 394.1 Input reflection coefficient versus frequency for <strong>dielectric</strong> (εr = 2.63) <strong>loaded</strong>open-ended waveguide radiator with length of L = 9.51mm 454.2 Stepped-<strong>horn</strong> <strong>antenna</strong> model 474.3 Input reflection coefficient versus frequency of εr = 1.5 <strong>dielectric</strong> loading of<strong>horn</strong> <strong>antenna</strong>s with uniform loading, step loading, linear loading and empty<strong>horn</strong> <strong>antenna</strong> 524.4 Gain versus frequency of <strong>dielectric</strong> (ε r = 1.5) <strong>loaded</strong> <strong>horn</strong> <strong>antenna</strong>s withuniform loading, step loading, linear loading and empty <strong>horn</strong> <strong>antenna</strong>. . . 534.5 Aperture efficiency versus frequency of <strong>dielectric</strong> (εr = 1.5) <strong>loaded</strong> <strong>horn</strong><strong>antenna</strong>s with uniform loading, step loading, linear loading and empty <strong>horn</strong><strong>antenna</strong>. 544.6 Cross-polarization level versus frequency of <strong>dielectric</strong> (εr = 1.5) <strong>loaded</strong> <strong>antenna</strong>swith uniform loading, step loading, linear loading and empty <strong>horn</strong> <strong>antenna</strong>. 554.7 Input reflection coefficient versus frequency of the <strong>dielectric</strong> (εr = 1.2, εr =1.5, εr = 1.7) <strong>loaded</strong> <strong>horn</strong> <strong>antenna</strong>s and empty <strong>horn</strong> <strong>antenna</strong>. 56ix
FigureLIST OF FIGURES(Continued)Page4.8 Gain versus frequency of the <strong>dielectric</strong> (ε r = 1.2, εr = 1.5, εr = 1.7) <strong>loaded</strong><strong>horn</strong> <strong>antenna</strong>s and empty <strong>horn</strong> <strong>antenna</strong>. 574.9 Aperture efficiency versus frequency of the <strong>dielectric</strong> (εr = 1.2, εr = 1.5 andεr = 1.7) <strong>loaded</strong> <strong>horn</strong> <strong>antenna</strong>s and empty <strong>horn</strong> <strong>antenna</strong>. 584.10 Cross-polarization level versus frequency of the <strong>dielectric</strong> (ε r = 1.2, εr = 1.5,εr = 1.7) <strong>loaded</strong> <strong>horn</strong> <strong>antenna</strong>s and empty <strong>horn</strong> <strong>antenna</strong>. 594.11 E-plane pattern versus 0° of the <strong>dielectric</strong> (ε r = 1.2, εr = 1.5, εr = 1.7)<strong>loaded</strong> <strong>horn</strong> <strong>antenna</strong>s and empty <strong>horn</strong> <strong>antenna</strong>. 604.12 H-plane pattern versus e° of the <strong>dielectric</strong> (εr = 1.2, εr = 1.5, εr = 1.7)<strong>loaded</strong> <strong>horn</strong> <strong>antenna</strong>s and empty <strong>horn</strong> <strong>antenna</strong>. 614.13 Input reflection coefficient versus frequency of the <strong>stepped</strong>-<strong>horn</strong> <strong>antenna</strong>s for(εr1 = 1.0 εr2 = 1 .0), (εr1 = 1.2 εr2 = 1.2), (εr1 = 1.0 ε r2 = 1.2),(εn = 1.2 εr2 = 1.0), and empty <strong>horn</strong> <strong>antenna</strong> with length L = 80.2 mm. . 624.14 Gain versus frequency of the <strong>stepped</strong>-<strong>horn</strong> <strong>antenna</strong>s for (ε r1 = 1.0 εr2 = 1.0),(εn = 1.2 εrg = 1.2), (εn = 1.0 εr2 = 1.2), (εn = 1.2 εrg = 1.0) andempty <strong>horn</strong> <strong>antenna</strong> with L = 80.2 mm. 634.15 Cross-polarization level versus frequency of the <strong>stepped</strong>-<strong>horn</strong> <strong>antenna</strong>s for(εr1 = 1.0 ε r 2 1.0), (εr1 = 1.2 εr2 = 1.2), (εr1 = 1.0 εr2 = 1.2),(εn = 1.2 εr2 = 1.0) and empty <strong>horn</strong> <strong>antenna</strong> with L = 80.2 mm. . . . . 644.16 Aperture efficiency versus frequency of the <strong>stepped</strong>-<strong>horn</strong> <strong>antenna</strong>s for (ε n =1.0 εr2 = 1.0), (ε r 1 = 1.2 εr2 = 1.2), (ε r1 = 1.0 εrg = 1.2), (ε r1 = 1.2εr2 = 1.0) and empty <strong>horn</strong> <strong>antenna</strong> with L = 80.2 mm. 654.17 Co- and Cross-polarization patterns for <strong>stepped</strong>-<strong>horn</strong> <strong>antenna</strong> (εr1 = 1.2 εr2 =1.2) and empty <strong>horn</strong> <strong>antenna</strong> with L = 80.2 mm at f = 10 GHz. 664.18 Amplitude of aperture magnetic field distribution,H x versus x and y for empty<strong>horn</strong> <strong>antenna</strong> with L = 80.2 mm at f = 10 GHz 674.19 Amplitude of aperture electric field distribution,Ey versus x and y for empty<strong>horn</strong> <strong>antenna</strong> with L = 80.2 mm at f = 10 GHz 684.20 Amplitude of aperture magnetic field distribution,H x versus x and y for (εri =1.0 εr2 = 1.0 )<strong>stepped</strong>-<strong>horn</strong> <strong>antenna</strong> at f = 10 GHz. 694.21 Amplitude of aperture electric field distribution,E y versus x and y for (ε n =1.0 εr2 = 1.0) <strong>stepped</strong>-<strong>horn</strong> <strong>antenna</strong> at f = 10 GHz. 70
- Page 1 and 2: Copyright Warning & RestrictionsThe
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- Page 6 and 7: APPROVAL PAGEVARIABLE PERMITTIVITY
- Page 8 and 9: To my parents, ..Tahsin and Güler
- Page 10 and 11: TABLE OF CONTENTSChapterPage1 INTRO
- Page 14 and 15: FigureLIST OF FIGURES(Continued)Pag
- Page 16 and 17: 2field uniformity and this results
- Page 18 and 19: 4from improving the gain, dielectri
- Page 20 and 21: Figure 2.1 Geometry of pyramidal a
- Page 22 and 23: 84Figure 2.4 Step discontinuity bet
- Page 24 and 25: 10section asFrom (2.4), the transve
- Page 26 and 27: 12and for the magnetic fieldIn the
- Page 28 and 29: 14where * shows complex conjugate.
- Page 30 and 31: 16where D is a diagonal matrix of t
- Page 32 and 33: 18Figure 2.6 Generalized reflection
- Page 34 and 35: 20aperture region and 11Ps is the m
- Page 36 and 37: 22where T; (x) and T: (y) are trian
- Page 38 and 39: 24where Γwghnk and r wg enk are th
- Page 40 and 41: tiTo determine the unknown coeffici
- Page 42 and 43: 28An electric vector potential F an
- Page 44 and 45: 30Using midpoint rule to evaluate i
- Page 46 and 47: 32whereGreen function integrals, 4,
- Page 48 and 49: 34taper and the phase distribution
- Page 50 and 51: 36Even though, TE10 mode is an inci
- Page 52 and 53: 38satisfy the amplitude ratio of 1/
- Page 54 and 55: 40would be slight deviation from th
- Page 56 and 57: 42increased to 15. Scattering matri
- Page 58 and 59: 44Table 4.4 Amplitude and Phase of
- Page 60 and 61: 46Figure 4.3, it is obvious that th
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48al = 0.73A, b1 = 0.34A and apertu
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50Table 4.7 Optimization Values of
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Figure 4.3 Input reflection coeffic
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Figure 4.5 Aperture efficiency vers
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Figure 4.7 Input reflection coeffic
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Figure 4.9 Aperture efficiency vers
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Figure 4.11 E-plane pattern versus
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62Figure 4.13 Input reflection coef
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Figure 4.16 Aperture efficiency ver
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Figure 4.18 Amplitude of aperture m
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Figure 4.20 Amplitude of aperture m
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Figure 4.22 Input reflection coeffi
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Figure 4.24 Cross-polarization leve
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751Figure 4.26 Amplitude of apertur
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770.8Figure 4.28 Amplitude of apert
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Figure 4.30 Amplitude of aperture e
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81Dielectric materials of various p
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The indefinite integrals associated
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BIBLIOGRAPHY[1] P. Clarricoats, A.
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87[26] T. Bird and S. Hay, "Mismatc