Dielectric Rod Antenna Array With Substrate Integrated Waveguide Planar Feed Network for Wideband Applications

Dielectric rod antenna (DRA) elements have numerous advantages over conventional waveguide and horn antenna elements. They have low insertion loss, broadband input match, high mutual decoupling efficiency, and low-cost manufacturing. Additionally, the radiation pattern of the dielectric rod antenna is almost frequency-independent. However, its feeding is generally a challenge. This paper demonstrates a novel ultra-wideband (UWB) eight-element DRA fed by a wideband substrate integrated waveguide (SIW) structure. The eight-way feed network has less than 1.1 dB insertion loss and only +/- 0.9 dB and +/- 4 degrees amplitude and phase imbalance, respectively. The developed low-cost and compact dual-layer DRA design covers over 40% bandwidth at X-band. It has a good input match, almost constant radiation pattern with a gain of 14.5 +/- 2 dB over the frequency band, low dispersion, low squint performance, and almost flat group delay, which are essential requirements for many UWB applications. The developed array antenna is compact and occupies only 10 x 9 cm(2).