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As the last example of spherical DRAs, we consider a spherical dielectric resonator with a coaxial probe feed as shown diagrammatically in Figure 25. The radius of the dielectric hemisphere is a = 12.5mm and its relative permittivity is ε_r = 9.8. The dielectric resonator is placed on a metallic ground plane of dimensions 60mm × 60mm and is fed by a coaxial transmission line of inner conductor radius r₁ = 0.63mm and outer conductor radius r₂ = 1.5mm. An air-filled coaxial line of these radii has a characteristics impedance of 50 Ohms. The coaxial cable is located underneath the ground plane and its outer conductor is grounded. The inner conductor of the coaxial probe is extended by a height of h = 6.5mm inside the dielectric block. The probe feed is offset from the center of the dielectric hemisphere by a length b = 6.4mm. To excite the coaxial probe in [[EM.Tempo]], it is extended downward by a length L_f = 15mm. A coaxial port is placed at the bottom of the coaxial feed line. Figure 26 shows the construction of the physical structure in [[EM.Tempo]], and Figure 27 shows the details of the coaxial feed.

To excite <table><tr><td>[[Image:ART DRA55A.png|thumb|left|480px|Figure 27: Details of the coaxial probe feed of the spherical DRA of Figure 26 with most objects in [[EMtheir freeze state.Tempo]], it is extended downward by a length L<sub/td>f</subtr> = 15mm. A coaxial port is placed at the bottom of the coaxial feed line. </table> Figure 27 28 shows the computed return loss (|S11|) of the probe-fed spherical dielectric resonator antenna simulated by [[EM.Tempo]]. Figure 28 29 shows the real and imaginary parts of the input impedance of the same antenna simulated by [[EM.Tempo]] and compares them with the measured data given by Ref. [8]. According to the analysis presented in Ref. [8], this particular DRA excites the TM₁₀₁ and TE₂₂₁ modes with very close resonant frequencies of 5.245GHz and 5.267GHz, respectively. Figure 29 30 shows the 3D far field radiation pattern of this spherical DRA at f = 4.5GHz.

[[Image:ART DRA56.png|thumb|left|550px|Figure 2728: Return loss of the coaxial-fed dielectric resonator antenna of Figure 26.]]

[[Image:ART DRA57.png|thumb|left|550px|Figure 2829: Real and imaginary parts of the input impedance of the dielectric resonator antenna of Figure 26, solid red line: [[EM.Tempo]] (FDTD) results for input resistance, solid blue line: [[EM.Tempo]] (FDTD) results for input reactance, red orange symbols: measured data given by Ref. [8] for input resistance, and blue turquoise symbols: measured data given by Ref. [8] for input reactance.]]

[[Image:ART DRA58.png|thumb|left|640px|Figure 2930: 3D far field radiation pattern of the spherical DRA with the coaxial feed computed at f = 4.5GHz by [[EM.Tempo]].]]