Segmented Hemispherical DRA: New Geometry Characterized and Investigated in Multi-Element Composite Forms for Wideband Antenna Applications

Hemispherical dielectric resonator antenna (HDRA) is reinvestigated by splitting it into four uniform quarters, which indeed generates a new DRA shape, proposed to call as "quarter-Hemispherical DRA" (q-HDRA). An innovative idea, gathered by the authors through their previous investigations, has been employed to investigate four-element q-HDRA resonating with dominant and first higher modes over a large impedance bandwidth (S-11 < -10 dB) and producing improved monopole-like radiation pattern. The improvement has been described in terms of uniformity and symmetry in the radiation patterns obtained consistently over the entire operating bandwidth. No degradation or compromise in impedance bandwidth is observed. For this purpose, the new DRA unit (q-HDRA) has been characterized using simulated and measured data. Prototypes of single and multi-element q-HDRA have been measured and compared with some earlier versions. Unlike earlier one, consistently symmetric monopole-like radiation from a four element q-HDRA has been demonstrated.