Design of a broadband dielectric resonator antenna and its application in low sensitivity frequency beam-scanning array with wide scanning angle and suppressed sidelobes

摘要

In this paper, a broadband dielectric resonator antenna (DRA) with a simpleH-slot feeding structure is proposed. The broad bandwidth (~45%) and unidirectionalradiation enable this DRA suitable to work as a radiation elementin the construction of a beam-scanning array with not only low frequency sensitivitywhich is important for accurate angle estimation of in-coming targets,but also a wide scanning range. Moreover, stable coupling coefficients areestablished around all the above three resonances with respect to itscorresponding feeding line, ensuring a low sidelobe level (SLL) across thewhole operating frequency range. In order to realize such a DRA, a latticedrectangular structure is utilized to generate the lower two resonances, whilethe upper resonance is generated by its H-shaped feeding slot. The shape ofthe latticed dielectric resonator is also modified according to a 3-D printed fixingstructure for an accurate installation. A 20-element beam-scanning prototypeis demonstrated and manufactured. The range of scanning angle is from−36° to +13° within the bandwidth of 10 to 16 GHz, corresponding to a frequencysensitivity of only 122.5 MHz/°. The achieved SLL are smaller than19 dB for all scanning beams. The above performance indicates that, this arrayis very suitable for near-range radar systems requiring an accurate angleestimation.