Broadband dual‐podal multilayer Vivaldi antenna array for remote sensing applications

Abstract

AbstractA novel wideband multilayer dual‐podal Vivaldi antenna with broadband characteristics from 5.5 to 20.82 GHz, is presented. Contrary to traditional Vivaldi antennas that are antipodal‐based, this design is realised by placing a pair of podal Vivaldi antennas with corrugated slots on the top and bottom of a substrate stack (consisting of two dielectric layers) using a Bondply. The pair is fed in‐phase with the help of a Strip‐Line (SL) transmission section that is terminated on a radial stub to couple capacitively to the antenna elements. With this technique of electrically coupling a podal Vivaldi pair, improved performance parameters are achieved, specifically: a measured maximum gain of 9.33 dBi, Half Power Beam Width of 126.5° in the H‐plane, and a maximum Front‐to‐Back (F/B) ratio of 14.36 dB with an overall antenna size of 29 × 21 × 1.63 mm. The in‐depth understanding of the working mechanism is supported by a detailed parametric analysis, current distribution, and a clear physical insight into the operating principles. Moreover, a 1 × 4 Vivaldi antenna array is also designed and analysed. A measured maximum gain of the 13 dBi at 15 GHz in the array is achieved along with the wide bandwidth of 6.3 GHz from 10.78 to 17.07 GHz. The array is fed through an SL corporate feed network that ensures in‐phase excitation of all four Vivaldi pairs. A Grounded Co‐planar Waveguide to SL transition is adopted for connecting the 2.92 mm Radio Frequency launcher on the top layer. The very compact geometry of the proposed structure enables its integration into the systems for remote sensing applications.