scholarly journals Miniaturized Antipodal Vivaldi Antenna with Improved Bandwidth Using Exponential Strip Arms

Electronics ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 83
Author(s):  
Mohammad Mahdi Honari ◽  
Mohammad Saeid Ghaffarian ◽  
Rashid Mirzavand

In this paper, a miniaturized ultra-wideband antipodal tapered slot antenna with exponential strip arms is presented. Two exponential arms with designed equations are optimized to reduce the lower edge cut-off frequency of the impedance bandwidth from 1480 MHz to 720 MHz, resulting in antenna miniaturization by 51%. This approach also improves antenna bandwidth without compromising the radiation characteristics. The dimension of the proposed antenna structure including the feeding line and transition is 158 × 125 × 1 mm3. The results show that a peak gain more than 1 dBi is achieved all over the impedance bandwidth (0.72–17 GHz), which is an improvement to what have been reported for antipodal tapered slot and Vivaldi antennas with similar size.

2021 ◽  
Vol 36 (6) ◽  
pp. 788-795
Author(s):  
Dalia Elsheakh ◽  
Osama Dardeer

This article presents a 2×1 CPW ultra wideband rectangular slot antenna array (UWB-RSAA) with a modified circular slot shape to support a high data rate for wireless communications applications. The proposed antenna array dimensions are 0.7λ×0.8λo×0.064λo at the resonant frequency 1.8 GHz. It is fabricated on Rogers RO4003 substrate and fed by using a coplanar waveguide (CPW). A graphene layer is added on one side of the substrate to realize frequency reconfigurability and improve the array gain. The proposed array acquires -10 dB impedance bandwidth of the RSAA that extends from 1.7 GHz to 2.6 GHz, from 3.2 to 3.8 GHz, and from 5.2 GHz to 7 GHz. The proposed array achieved a realized peak gain of 7.5 dBi at 6.5 GHz at 0 Volt bias with an average gain of 4.5 dBi over the operating band. When the graphene bias is increased to 20 Volt, the antenna bandwidth extends from 1 GHz to 4 GHz and from 5 to 7 GHz with a peak gain of 14 dBi at 3.5 GHz and an average gain of 7.5 dBi. The linearly polarized operation of the proposed array over the operating bands makes it suitable for short-range wireless communications .


2017 ◽  
Vol 2017 ◽  
pp. 1-8
Author(s):  
Marko Sonkki ◽  
Sami Myllymäki ◽  
Jussi Putaala ◽  
Eero Heikkinen ◽  
Tomi Haapala ◽  
...  

The paper presents a novel dual polarized dual fed Vivaldi antenna structure for 1.7–2.7 GHz cellular bands. The radiating element is designed for a base station antenna array with high antenna performance criteria. One radiating element contains two parallel dual fed Vivaldi antennas for one polarization with 65 mm separation. Both Vivaldi antennas for one polarization are excited symmetrically. This means that the amplitudes for both antennas are equal, and the phase difference is zero. The orthogonal polarization is implemented in the same way. The dual polarized dual fed Vivaldi is positioned 15 mm ahead from the reflector to improve directivity. The antenna is designed for -14 dB impedance bandwidth (1.7–2.7 GHz) with better than 25 dB isolation between the antenna ports. The measured total efficiency is better than -0.625 dB (87%) and the antenna presents a flat, approximately 8.5 dB, gain in the direction of boresight over the operating bandwidth whose characteristics promote it among the best antennas in the field. Additionally, the measured cross polarization discrimination (XPD) is between 15 and 30 dB and the 3 dB beamwidth varies between 68° and 75° depending on the studied frequency.


2019 ◽  
Vol 8 (3) ◽  
pp. 57-63
Author(s):  
A. Zitouni ◽  
N. Boukli-Hacene

In this article, a novel T-shaped compact dielectric resonator antenna for ultra-wideband (UWB) application is presented and studied. The proposed DRA structure consists of T-shaped dielectric resonator fed by stepped microstrip monopole printed antenna, partial ground plane and an inverted L-shaped stub. The inverted L-shaped stub and parasitic strip are utilized to improve impedance bandwidth. A comprehensive parametric study is carried out using HFSS software to achieve the optimum antenna performance and optimize the bandwidth of the proposed antenna. From the simulation results, it is found that the proposed antenna structure operates over a frequency range of 3.45 to more than 28 GHz with a fractional bandwidth over 156.12%, which covers UWB application, and having better gain and radiation characteristics.


Frequenz ◽  
2017 ◽  
Vol 71 (5-6) ◽  
Author(s):  
Yosita Chareonsiri ◽  
Wanwisa Thaiwirot ◽  
Prayoot Akkaraekthalin

AbstractIn this paper, the tapered slot antenna (TSA) with corrugation is proposed for UWB applications. The multi-section binomial transformer is used to design taper profile of the proposed TSA that does not involve using time consuming optimization. A step-by-step procedure for synthesis of the step impedance values related with step slot widths of taper profile is presented. The smooth taper can be achieved by fitting the smoothing curve to the entire step slot. The design of TSA based on this method yields results with a quite flat gain and wide impedance bandwidth covering UWB spectrum from 3.1 GHz to 10.6 GHz. To further improve the radiation characteristics, the corrugation is added on the both edges of the proposed TSA. The effects of different corrugation shapes on the improvement of antenna gain and front-to-back ratio (F-to-B ratio) are investigated. To demonstrate the validity of the design, the prototypes of TSA without and with corrugation are fabricated and measured. The results show good agreement between simulation and measurement.


Micromachines ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 453
Author(s):  
Sharadindu Gopal Kirtania ◽  
Bachir Adham Younes ◽  
Abdul Rakib Hossain ◽  
Tutku Karacolak ◽  
Praveen Kumar Sekhar

In this article, an inkjet-printed circular-shaped monopole ultra-wideband (UWB) antenna with an inside-cut feed structure was implemented on a flexible polyethylene terephthalate (PET) substrate. The coplanar waveguide (CPW)-fed antenna was designed using ANSYS high-frequency structural simulator (HFSS), which operates at 3.04–10.70 GHz and 15.18–18 GHz (upper Ku band) with a return loss < −10 dB and a VSWR < 2. The antenna, with the dimensions of 47 mm × 25 mm × 0.135 mm, exhibited omnidirectional radiation characteristics over the entire impedance bandwidth, with an average peak gain of 3.94 dBi. The simulated antenna structure was in good agreement with the experiment’s measured results under flat and bending conditions, making it conducive for flexible and wearable Internet of things (IoT) applications.


2021 ◽  
Author(s):  
Dalia Elsheakh ◽  
Osama Dardeer

Abstract This article presents a 2×1 CPW ultra wideband rectangular slot antenna array (UWB-RSAA) with modified circular slot shape to support high data rate for wireless communications applications. The proposed antenna array dimensions are 0.7λo×0.8λo×0.064λo at the resonant frequency 1.8 GHz and it is fabricated on a commercially available rogers RO4003 substrate (with εr = 3.5), which is fed by using coplanar waveguide (CPW). A graphene layer is added on the other side of the substrate to achieve frequency reconfigurable and improve the antenna array gain. The -10 dB impedance bandwidth of the RSAA extends from 1.7 GHz to 2.6 GHz, from 3.2 to 3.8 GHz and from 5.2 GHz to 7 GHz with peak gain of 7.5 dBi at 6.5 GHz at 0 Volt bias over the operating band with average gain of 4.5 dBi. When the graphene bias is increased to 20 Volt, the antenna bandwidth extend from 1 GHz to 4 GHz and from 5 to 7 GHz with array peak gain 14 dBi at 3.5 GHz and average gain 7.5 dBi. The proposed array achieved linear polarized behaviour over the operating bands to be suitable for short range UWB wireless communications and object detection. All simulation carried out using 3D high frequency structure simulator (HFSS) Ansys ver. 15.


Frequenz ◽  
2015 ◽  
Vol 69 (11-12) ◽  
Author(s):  
R. V. S. Ram Krishna ◽  
Raj Kumar

AbstractIn this paper, a printed slot antenna for ultra-wideband dual polarization is proposed and experimentally demonstrated. The slot is L-shape and its two arms are individually microstrip fed for producing the orthogonal polarizations. The slot arms and the microstrip feed lines are step sectioned for wideband impedance matching. For isolation purpose, a slant narrow metallic stub is inserted at the junction of the slot arms. The antenna has an impedance bandwidth of 118% (3.1–12 GHz) and isolation of around 20 dB over most of the band. The radiation patterns are nearly omnidirectional with a peak gain varying from 3 to 6 dBi. For assessing the diversity performance of the antenna, the envelope correlation coefficients are computed from the simulated and measured S-parameters and found to be within acceptable limits. With a compact, single substrate design, the antenna is expected to be useful for printed circuit ultra wideband applications requiring dual polarization features.


2021 ◽  
Author(s):  
Sathishkumar N ◽  
Nandalal V ◽  
Rajesh Natarajan

Abstract Dual mode antipodal Vivaldi antenna (AVA) with narrowband to wideband switching is proposed in this work. The antenna has the footprint of 60 mm x 40 mm x 1.6 mm and FR-4 substrate used for fabrication. The antenna exhibits 8.3 GHz bandwidth in wideband mode with a peak gain of 6.9 dBi and 1.6 GHz bandwidth in narrowband mode with a peak gain of 7 dBi. The simulations are performed using CST full wave simulator and the results are compared with the reference antenna of the same dimensions. PIN diodes are implemented to achieve the frequency switching. The working principle of the antenna is explained through simulation and verified through measurements.


Electronics ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 2169
Author(s):  
Syifa Haunan Nashuha ◽  
Gwan Hui Lee ◽  
Sachin Kumar ◽  
Hyun Chul Choi ◽  
Kang Wook Kim

The design and implementation of an ultra-wideband trapezoidal log-periodic antenna (LPA) integrated with an elliptical dielectric lens are presented. The proposed LPA is fed by an ultra-wideband microstrip-to-coplanar stripline transition structure. In order to improve the radiation patterns and to increase the antenna gain, an elliptical dielectric lens is mounted on the top of the LPA radiator. The design parameters of the elliptical lens integrated with the LPA were optimized through a parametric analysis. The proposed antenna shows an impedance bandwidth (S11 ≤ −10 dB) from 5.2 to 40 GHz, with a peak gain of 17.8 dB.


2019 ◽  
Vol 2019 ◽  
pp. 1-14 ◽  
Author(s):  
Guang Sun ◽  
Ge Gao ◽  
Tingting Liu ◽  
Yi Liu ◽  
Hu Yang

In this paper, a wideband slot antenna element and its array with stereoscopic differentially fed structures are proposed for the radar system. Firstly, a series of slots and a stereoscopic differentially fed structure are designed for the antenna element, which makes it possess a wide bandwidth, stable radiation characteristics, and rather high gain. Moreover, the stereoscopic feeding structure can firmly support the antenna’s radiation structure and reduce the influence of feeding connectors on radiating performance. Secondly, a 4 × 4 array is designed using the proposed antenna element. And a hierarchical feeding network is designed for the array on the basis of the stereoscopic differentially fed structure. For validation, the antenna element and 4 × 4 array are both fabricated and measured: (1) the measured −10 dB impedance bandwidth of the antenna element is 62% (6.8–12.9 GHz) and the gain within the entire band is 5–9.7 dBi and (2) the measured −10 dB impedance bandwidth of the array is approximately 50% (7 to 12 GHz) with its gain being 14–19.75 dBi within the entire band. Notably, measured results agree well with simulations and show great advantages over other similar antennas on bandwidth and gain.


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