Palm tree coplanar Vivaldi antenna for near field radar application

Abstract

The Vivaldi antenna is an ultra‐wideband device that has high gain and directional radiation pattern. This paper performs a comparison of conventional, regular and exponential edges of a Palm Tree Vivaldi antenna that could operate in L and S band frequencies. The conventional coplanar Vivaldi antenna (C‐CVA), regular coplanar Vivaldi antenna (R‐CVA), exponential slot edge coplanar Vivaldi antenna (ESE‐CVA), regular antipodal Vivaldi antenna (R‐AVA) and exponential slot edge antipodal Vivaldi antenna (ESE‐AVA), all with the same dimensions, are compared in terms of reflection coefficient and radiation pattern performance. Gain improvement is achieved as 6.22, 7.64, 7.90, 7.92, and 10.74 dB at 3 GHz respectively for R‐AVA, ESE‐AVA, Convetional ‐ Coplanar Vivaldi Antenna, R‐CVA, and ESE‐CVA. The number, height, and opening rate of slot edges predispose current distribution and radiation pattern of CVA. Our results show that the exponential slot edge coplanar Vivaldi antenna provides the best gain and derives the best side lobe level, which confirmed the possibility of applying the Palm Tree technique to coplanar Vivaldi antennas, in addition to the antipodal ones, as originally proposed.

A novel Vivaldi antenna for UWB detection

“…The TDR signal s(i) is used to obtain signal module ab(i) by applying the absolute function, as expressed in (14). The envelope function is then used to extract the local maximum of the signal ab(i) through the derivative relation to form the envelope signal en(i), as shown in (15). Finally, according to (16), the third-order quadratic function is used to enhance the signal en(i) energy intensity and obtain signal qu(i).…”

“…Finally, according to (16), the third-order quadratic function is used to enhance the signal en(i) energy intensity and obtain signal qu(i). s i ta i bg i ( ) = ( ) − ( ), (13) ab i s i ( ) = ABS( ( )), (14) en i ab i ( ) = ENV( ( )), (15) qu i en i en i en i ( ) = ( ( ))*( ( ))*( ( )).…”

“…In Abbak et al, 11 a Vivaldi antenna with rectangular slots at both ends of the patch was proposed to widen the operating frequency band. Similarly, VA with irregular pencil‐shaped slots on the patch surface, 12 VA with rod‐shaped slots on both sides of the patch, 13 antipodal Vivaldi antenna (AVA) with comb‐shaped slots structure, 14 AVA with genic palm tree slots, 15 AVA etched rectangular slots and loaded resistance, 16 VA with a fern fractal leaf structure, 17 and triangular slots etched VA 18 were designed to obtain a lower return loss to reduce the power loss. The connecting strip was combined with the middle exponential slot to balance the surface current 19 .…”

The Performance Enhancement of Triple-band Vivaldi Antenna using SIW Structure for IIoT applications

“…The open microstrip Lm1 and uniform slot line Ls1 are calculated approximately by l0/4 where l0 is the wavelength at the center frequency f0 [21]. The exponential taper can be determined by [22]:…”

Designing and building radio frequency devices with tailored dielectric properties using additive manufacturing

“…To demonstrate the potentiality of this technique for RF applications, we devised an RF device, considering how the variation of $${\varepsilon }_{r}$$ along the object could change the path of the microwave signal emitted by a planar ultra‐wideband (UWB) antenna. We chose the palm tree antipodal Vivaldi antenna (AVA) as the reference antenna for the experiments 15,16 . The main goal here is to demonstrate the potentiality of the technique to design and build RF devices with tailored dielectric patterns, particularly to improve the properties of RF devices, such as a planar antenna.…”