A Miniaturized Series Fed Tri-Slot Coplanar Vivaldi Antenna for RADAR Application with Reduced Ground Plane Effect

In this article, a printed series fed tri-slot coplanar Vivaldi antenna is studied and investigated for RADAR application. The antenna consists of three exponentially tapered slots excited by a single microstrip line. The three slots are series fed simultaneously with a radial stub on the microstrip feed line for impedance matching. The proposed antenna covers a frequency of 7.8-11.8 GHz at -10 dB impedance bandwidth. The antenna gain varies from 7.5 dB at the lowest operating frequency and increases to around 9.5 dB at the center frequency of 10 GHz. A key versatility of the proposed design is the ability to modify the ground plane size without affecting the antenna impedance and gain. This makes the antenna suitable to incorporate RADAR transceiver components without modifying the existing antenna design. The proposed antenna is fabricated and measured results show good agreement with simulated results.