Indian Journal of Science and Technology

Abstract

Objectives: To design high bandwidth and high gain compact antipodal Vivaldi antenna which can be applied for modern communication systems especially for military communication systems. Methods/Analysis: Antipodal Vivaldi antenna is designed with flared elements on both sides of the substrate. Top side patch element is oriented towards left side and bottom side defected ground structured element is oriented towards right side. Finite element method based HFSS-15 is used in the design and simulation. The simulated EM-Results of the return loss, VSWR, radiation patterns and field distributions are analyzed and optimized antipodal vivaldi antenna is designed with parametric analysis. Fire resistance PCB substrate material with dielectric constant 4.4 is used as substrate to prototype the antenna model and measured results are analyzed for validation on ZNB 20 vector network analyzer. Findings: In this work a novel antipodal Vivaldi antenna is designed to operate between L to KU-band communication and applications. The proposed antenna modal consisting of a special type of tapered slot edge structure in the design which enhanced the bandwidth of the antenna. To convert antenna into a wide band model, some modifications are done by placing slotted sections on the ground and patch elements. Antenna is showing 15 GHz huge bandwidth and impedance bandwidth of more than 65%. The proposed antenna is showing VSWR of 2:1 ratio in the operating band and peak realized gain of 7 dB. Omni directional radiation pattern with peak directivity of 5 dB is attained with the current model. Wideband characteristics with considerable gain grouping this antenna in to several communication applications in S, C, X, Ku-bands. Novelty/Improvement: Novelty with respect to defected ground structured flared element and huge bandwidth are advancements in the current design. Both patch and ground structures are designed in a way to enhance the bandwidth as well as gain which is advantageous in communication applications. Field distributions with excellent radiation characteristics are making this model as suitable candidate for future communication systems. 
Keywords: Antipodal Vivaldi Antenna (AVA), Ansys High Frequency Structure Simulator (HFSS), Bandwidth, Tapered Slot (TS), Vector Network Analyzer