Defected ground structure based compact UWB dielectric resonator antennas with enhanced bandwidth

This article introduces two new compact ultra-wide band (UWB) rectangular dielectric resonator antennas (RDRAs) with enhanced bandwidth (BW), gain, and directivity. The RDRAs are designed at 10 GHz resonant frequency. The proposed RDRAs are compactly designed using resonating dielectric material (RDM) of Alumina_96 pct (e(r) = 9.4, tand = 0.006) with overall dimensions of 30 x 20 x 4.6 mm(3). The RDMs are mounted on FR4 substrate (e(r) = 4.4, tand = 0.02) with defected ground structure (DGS). The DGS are comprised of rectangular and circular ring slots on it. These compact DGS-RDRAs provides enhanced BW. Prototypes of the two suggested RDRAs are fabricated. The fabricated RDRAs are validated by experimental set-ups. The RDRA with rectangular-ring slot DGS provides impedance BW (S-11 < -10 dB) of 33.97 % (8.6658-12.071 GHz). The impedance BW of the other RDRA is 27.97 % (9.08-11.869 GHz). The rectangular-ring slotted RDRA offers radiation efficiency and peak realized gain of 86.4 % and 6.27 dBi, respectively within the band of operating frequencies. The radiation efficiency and realised gain of circular-ring slotted RDRA are 86.18 % and 5.9 dBi, respectively. Good agreements are achieved in between the simulated results and measured results. The results are compared with some recently developed antennas available in literature. The comparison shows that the proposed RDRAs can be suitable candidate for various X-band applications such as satellite downlinks, synthetic aperture radar, weather monitoring by military and some government organizations.