Changes

Next, we will examine a strip-fed cylindrical dielectric resonator antenna design as shown in Figure 2930. The dielectric block has a radius of a = 10.3mm and a height of h = 34.3mm with a relative permittivity of ε_r = 9.4. A vertical metal strip of length L = 12mm and width w = 1mm is used to excite the cylindrical dielectric resonator in a similar manner to the rectangular DRA of Figure 2. Similarly, one One can use either the dielectric waveguide model (DWM ) or tranverse resonance method (TRM methods ) to derive the characteristic equation of the HEM_mnl modes of the cylindrical dielectric resonator. These equations involve a combination of the Bessel functions of the first kind J_n(x) and the modified Bessel functions of the second kind K_n(x). According to the analysis presented by Ref. [3], this particular cylindrical DRA shown in Figure 29 30 supports the HEM₁₁₁ and HEM₁₁₃ modes with resonant frequencies 2.90GHz and 3.72GHz, respectively. Figure 31 shows the FDTD mesh of the cylindrical DRA generated by [[EM.Tempo]] using a mesh density of 30 cells per wavelength along with high precision adaptive mesh settings.

[[Image:ART DRA60.png|thumb|left|480px|Figure 2930: Geometry of a cylindrical dielectric resonator antenna with a vertical metallic strip feed on its edge.]]

[[Image:ART DRA61.png|thumb|left|480px|Figure 3031: FDTD mesh of the cylindrical DRA with an edge strip feed.]]

This problem was simulated using [[EM.Tempo]], and the computed reutrn return loss of the DRA is plotted in Figure 3132. This figure also shows the simulated and measured results presented by Ref. [3]. The simulated results were obtained using ANSYS HFSS based on the finite element method (FEM). Similar to the previous case, the dimensions of the metallic ground plane were not given in Ref. [3]. Both [[EM.Tempo]] and Ref. [3] show a 10-dB bandwidth of 800MHz, but [[EM.Tempo]]'s bandwidth is shifted up by 200MHz starting at 4.25GHz and ending at 4.05GHz.