Analysis Of Slot Arrays In Single-ridged Trapezoidal Waveguides And Applications

In this thesis, a study of slot arrays, operating at Ku band, in single-ridged trapezoidal waveguides and its application to azimuthal omnidirectional antennas were undertaken. The thesis is divided into Part I and Part II. In Part I, a moment method analysis of isolated longitudinal slots in single-ridged trapezoidal waveguides is presented. The computed s parameters of the slot are compared with the measured ones. At the end of Part I, the experimental and theoretical H-plane pattern and input VSWR of the designed ten-slot resonant array are discussed. Part II covers the computations of the characteristics of azimuthal omnidirectional antennas, a designed example of high-gain azimuthal omnidirectional antenna of slotted single-ridged trapezoidal waveguide arrays, and the improved design procedures for the omnidirectional antenna. The main contributions of the author抯 work are as follows: (I) Based on multiresolution analysis, a method for computation of TE and TM modes in arbitrary cross sections is presented. Numerical examples for various waveguides show the validity and effectiveness of the method. Because of the field expression in the simple series fonn, the proposed method is flexible for the mathematical operations. (2) The characteristics of longitudinal slots with rectangular ends in single-ridged trapezoidal waveguides are studied by moment method. The numerical computations are compared with experimental results of slots with rounded ends. The data are useful for designs of slotted waveguide antennas. (3) A ten-slot resonant array fed by the single-ridged trapezoidal waveguide is designed. At operating band, the experimental H-plan pattern is in good agreement with theoretical pattern. (4) An accurate computation, using moment method, of characteristics of the junction of coaxial to radial waveguide is presented. The dimensions of the junction with maximum transmission are determined by the numerical results. (5) Evaluation of the properties of azimuthal antennas with slot arrays on the circular or approximate circular conducting cylinder is described. Most of the computations are in agreement with experimental data. (6) A high-gain azimuthal omnidirectional antenna (>13dB) of slotted single-ridged waveguide arrays is designed. By analyzing measured pattern and input VSWR, the improved design procedures are provided. +...