Theoretical and experimental investigations on different triangular shaped radiators

Abstract

ABSTRACT In this doctoral dissertation, theoretical and experimental investigations on various triangular shaped Microstrip Antennas (MAs) and Dielectric Resonator Antennas (DRAs) are presented in a systematic way irrespective of their applications if any. For theoretical investigation, the antenna is modeled here as a “Cavity”. Wave equation is solved within the cavity (here, antenna) for a given boundary conditions first to find the approximate solution of the eigenfunction. Internal electric and magnetic fields are plotted using conventional „slope method‟ (or gradient method) to identify various modes. Radiation characteristics of a particular mode are then investigated. Input impedance, far-field patterns, total Q-factor, radiated power, gain, bandwidth, radiation efficiency etc. are investigated. Closed form expressions are given here to predict the input impedance and far-field radiation patterns for different modes. Literature survey shows that Rectangular DRA (RDRA) has been investigated at fundamental mode only using magnetic dipole moment. The untouched areas (i.e. input impedance, far-field patterns, total Q-factor, radiated power, gain, bandwidth, radiation efficiency etc.) on RDRA are also investigated here for different modes. In this doctoral dissertation, radiation characteristics are presented for: Equilateral Triangular Microstrip Antenna (ETMA) 30°–60°–90° Triangular Microstrip Antenna (TMA) 45°–45°–90° TMA Isosceles TMA. Rectangular DRA (RDRA) Equilateral Triangular Dielectric Resonator Antenna (ETDRA) 30°–60°–90° Triangular Dielectric Resonator Antenna (TDRA) 45°–45°–90° TDRA. Isosceles TDRA. Inhomogeneous RDRA. A simple, novel and time efficient procedure is developed to compute singularity free expressions for computing far-field radiation patterns of any antenna with rectilinear symmetry. This technique is also extended here to compute stored energy, dielectric loss, conductor loss etc. It is found that our analytical solutions can predict the results orders faster than numerical EM simulators. Typical results are shown in Table 1 with respect to rectangular and triangular shaped antennas. For this comparison, a personal computer having Core 2 duo Intel processor and 3GB RAM is used. Table 1 Comparison of Time between Analytical Solution and EM Simulators SL No Antenna Mode Time (seconds) Numerical EM Simulator Analytical Theory (our) IE3D HFSS CST 1 Rectangular MA 156 189 169 2.86 162 194 208 1.89 2 Equilateral TMA 194 284 302 2.45 211 327 311 2.66 3 Rectangular DRA - 246 352 2.72 - 277 324 2.81 4 Equilateral TDRA - 338 355 2.89 - 341 379 2.82 Our analytical solutions can efficiently be utilized as entire domain full-wave MoM analysis. Further, the results of these theoretical investigations can easily be extended to the cases of triangular shaped waveguides, filters, oscillators, cavities etc.