A miniaturized multi-octave Vivaldi antenna for electronic warfare systems

Antennas with multi-octave bandwidth are widely used for applications such as phased arrays, electronic warfare, and radar navigation due to wide bandwidth, high gain, wide beam width, and flat conformal characteristics. Tapered slot antennas and their variants are classic example of such multi-octave radiators. In this paper, a miniaturized tapered slot multi-octave Vivaldi antenna (L x W x h = 40 x 20 x 1.6 mm(3)) in the frequency range 6-18 GHz is presented. The optimized dimensions of the antenna are determined through parametric studies to make the antenna suitable to operate in the desired frequency band. A prototype of the proposed antenna is fabricated using FR4 substrate with dielectric constant of 4.4. The return loss, gain, and radiation patterns in E-H planes are measured through simulation (Ansys HFSS-15.0 software) and experimentation. It is verified that the antenna provides moderate gain of 4.4 dB at 18 GHz frequency and radiation patterns are unidirectional and satisfactory. The primary advantage of the proposed antenna is its miniaturized size and simple structure.