Design of a Compact Dielectric Resonator Antenna with Flat-top Radiation Pattern

The utilization of a transmitting antenna with flat-top radiation patterns is demanded in many applications. However, the existing antennas with flat-top radiation patterns usually have complex structures and bulky sizes. In this work, a new stacked rectangular dielectric resonator antenna (DRA) is proposed to implement flat-top radiation patterns by combining TE
^y
133
and TE
^x
223
modes of a rectangular DRA. The gain is improved by stacking a small DR with grooves. For validation, a flat-topped DRA operating at 5.8 GHz is designed. Stable flat-top patterns can be maintained from 5.78 GHz to 5.84 GHz. The 3-dB beamwidths are 87° and 58° in the φ = 0° and φ = 90° planes, respectively. And the relative sidelobe levels (SLLs) are lower than -13 dB in both planes. The comparison between the proposed antenna and relevant works implies that the compactness and simplicity in structure of the proposed antenna.