Variable permittivity dielectric material loaded stepped-horn antenna

More documents

Recommendations

Info

42increased to 15. Scattering matrix size became 30 x 30 which is much larger than 6 x 6used in the case of an empty horn.Table 4.1 Amplitude and Phase of Reflection and Transmission Coefficients of TE10Mode in an Empty Horn of Length L = 2.5A and Free Space Wavelength A = 0.03m.Table 4.2 Amplitude and Phase of Reflection and Transmission Coefficient of a TE Nmode in a Dielectric (εr = 2.5) Loaded Horn Antenna of Length L = 2.5A. A is theWavelength Inside the Dielectric Medium.The magnitude and phase of the reflection and transmission coefficients of the dominantTE10 mode at the feed section are checked to examine the overall convergence of the modematching technique versus the total mode number, NT. Consider horn antenna with theinput feed section dimensions of x 1 = 0.75A and y 1 = 0.3A and aperture dimensions ofa2 = 2.7A and b2 = 1.2A and the length of the tapered section L = 2.5A. Number ofsteps are chosen as A r = 75. Power density carried by the incident TE10 mode is assumed
43to be equaled to 1 Watt/m². Table 4.3 shows convergence of the magnitude of the inputreflection coefficent, its dependence on the total mode number used in calculations for anempty and εr = 3 dielectric loaded horn antennas. As seen from Table 4.3 and Table4.4, 10 modes for the empty horn and 20 modes for the dielectric loaded horn antenna areenough to observe convergence. Total number of modes, NT in each waveguide depend onthe physical dimensions and the permittivity of loading dielectric material. Total numberof sections, NI and number of modes, NT used in all the subsequent calculations, weredetermined based on above mentioned criteria.Table 4.3 Amplitude and Phase of Reflection and Transmission Coefficient of TE 10 Modein an Empty Horn Antenna of Length L = 2.5 A. A is a Free Space Wavelength.The entire analysis were coded in MATLAB. The validity of the code developed inthis dissertation has been verified using experimental data available in the literature. Sincethere is no study available pertaining to a dielectric loaded horn antenna, verification iscarried out in two phases. First, 20 dB standard gain horn antenna gain and VSWR arecompared with the experimental results [11] . It can be seen from Table 4.5 that the theoryand measured results agreed well.
Page 1 and 2:
Copyright Warning & RestrictionsThe
Page 4 and 5:
VARIABLE PERMITTIVITY DIELECTRIC MA
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 12 and 13: LIST OF FIGURESFigurePage2.1 Geomet
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 58 and 59: 44Table 4.4 Amplitude and Phase of
Page 60 and 61: 46Figure 4.3, it is obvious that th
Page 62 and 63: 48al = 0.73A, b1 = 0.34A and apertu
Page 64 and 65: 50Table 4.7 Optimization Values of
Page 66 and 67: Figure 4.3 Input reflection coeffic
Page 68 and 69: Figure 4.5 Aperture efficiency vers
Page 70 and 71: Figure 4.7 Input reflection coeffic
Page 72 and 73: Figure 4.9 Aperture efficiency vers
Page 74 and 75: Figure 4.11 E-plane pattern versus
Page 76: 62Figure 4.13 Input reflection coef
Page 79 and 80: Figure 4.16 Aperture efficiency ver
Page 81 and 82: Figure 4.18 Amplitude of aperture m
Page 83 and 84: Figure 4.20 Amplitude of aperture m
Page 85 and 86: Figure 4.22 Input reflection coeffi
Page 87 and 88: Figure 4.24 Cross-polarization leve
Page 89 and 90: 751Figure 4.26 Amplitude of apertur
Page 91 and 92: 770.8Figure 4.28 Amplitude of apert
Page 93 and 94: Figure 4.30 Amplitude of aperture e
Page 95 and 96: 81Dielectric materials of various p
Page 97 and 98: The indefinite integrals associated
Page 99 and 100: BIBLIOGRAPHY[1] P. Clarricoats, A.
Page 101 and 102: 87[26] T. Bird and S. Hay, "Mismatc
show all

Variable permittivity dielectric material loaded stepped-horn antenna

Create successful ePaper yourself

Delete template?

Save as template?