Design of a fractal inspired antipodal vivaldi antenna with enhanced radiation characteristics for wideband applications

Abstract

A novel fractal inspired antipodal Vivaldi antenna is proposed for wideband applications. A step‐by‐step procedure has been employed to design and optimise the performance of the proposed antenna. First, a conventional antipodal Vivaldi antenna (CAVA) is designed as a reference antenna and then a Koch fractal‐shaped parasitic lens is introduced in the CAVA. Finally, a fractal‐shaped dielectric lens has been added as an extension of the antenna substrate. The presence of parasitic fractal lens in the flare aperture and fractal dielectric lens enhances the antenna bandwidth and also improves field coupling between the antenna arms and produces stronger radiation in the end fire direction which in turn increases the gain and directivity of the antenna. The optimised antenna is fabricated and tested showing|S11| below −10 dB from 4.2–42 GHz band. The dimension of the proposed antenna is 186 × 66 × 1.524 mm3. Results show that |S11| characteristics and other parameters are in good agreement with the simulation counterpart.

Miniaturized Antipodal Vivaldi Antenna with Improved Bandwidth Using Exponential Strip Arms

“…Several researchers have introduced different methods to increase the antenna directivity [20][21][22][23]. Various lens structures such as metamaterial-loaded [21], fractal inspired [22], and phase adjusted [23] structures were proposed to be placed in front of the radiating area to improve the antenna directivity and radiation characteristics of Vivaldi antennas. Using one of these techniques could increase the directivity of the proposed antenna if higher gain is required.…”

Fractal antennas and arrays: a review and recent developments

“…A miniaturized hexagonal-triangular fractal antenna is presented in [138] for wide-band applications that offered the bandwidth of 3-25.2 GHz. A new approach has been proposed in [139] for improving the gain, directivity, and bandwidth of a conventional AVA. Inserting a fractal-shaped parasitic lens in the antenna aperture and fractal-shaped dielectric lens in the radiation aperture of the antenna is found to be an effective approach without compromising the size of the antenna.…”

Design of an antipodal Vivaldi antenna with fractal‐shaped dielectric slab for enhanced radiation characteristics

“…The design and simulation of the proposed antenna have been opted using electromagnetic simulation software CST Microwave Studio. The CAVA is shown in the Figure 1A along with the proposed antenna, which has shown in Figure 1B. The 3D view and side view have been shown in Figure 1C,D, respectively.…”

“…In Reference , to boost the gain and front‐to‐back ratio of the antenna at a higher frequency, comb‐shaped slits inscribed on the boundary of the radiator and ground plane. An AVA for wideband application is presented in Reference where Koch fractal‐shaped parasitic lens is introduced in the aperture section of the antenna to enhance the gain and directivity. Another dielectric lens of Koch fractal shape also added for further improvement of antenna performance.…”