Extending the Low Frequency Limit of Tightly Coupled Dipole Arrays for Ultra-Wide Bandwidth With Ultra-Thin Profile

This paper proposes a flexible PCB based design for an ultra-wideband tightly coupled dipole array (TCDA) with an ultra-thin profile. The design approach involves increasing the capacitance between the dipole and the coupling patch, which compensates for ground inductance and effectively lowers the...

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Main Authors: Rajbala Solanki, Peng Khiang Tan, Theng Huat Gan
Format: Article
Language:English
Published: IEEE 2024-01-01
Series:IEEE Access
Subjects:
Online Access:https://ieeexplore.ieee.org/document/10786023/
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author Rajbala Solanki
Peng Khiang Tan
Theng Huat Gan
author_facet Rajbala Solanki
Peng Khiang Tan
Theng Huat Gan
author_sort Rajbala Solanki
collection DOAJ
description This paper proposes a flexible PCB based design for an ultra-wideband tightly coupled dipole array (TCDA) with an ultra-thin profile. The design approach involves increasing the capacitance between the dipole and the coupling patch, which compensates for ground inductance and effectively lowers the low frequency, thereby enhancing the bandwidth. The proposed configuration integrates a TCDA on an ultra-thin flexible PCB, a resistive frequency selective surface (FSS), and a balun (i.e. BALanced to UNbalanced feed transformation) constructed using a tapered microstrip line (MSL). By incorporating the FSS layer, ground reflection effects are effectively mitigated, leading to improved bandwidth. Additionally, the use of an ultra-thin flexible PCB (explored for the first time in TCDAs, to the best of our knowledge) allows the TCDA to extend its low frequency limit, further contributing to bandwidth enhancement. However, utilizing an ultra-thin flexible PCB poses fabrication challenges, such as maintaining uniform separation from the ground plane and difficulties with soldering etc. Numerical simulations indicate that the TCDA array achieves a bandwidth of approximately 24:1. The overall profile of the array is approximately <inline-formula> <tex-math notation="LaTeX">$\lambda _{L}$ </tex-math></inline-formula>/25, (where <inline-formula> <tex-math notation="LaTeX">$\lambda _{L}$ </tex-math></inline-formula> is the wavelength at the lowest frequency of operation) and it has an average radiation efficiency of 66%. To verify the accuracy of the simulation results, an <inline-formula> <tex-math notation="LaTeX">$8.5\times 8.5$ </tex-math></inline-formula> array prototype is fabricated and measurements are performed. The measured results closely align with the simulated outcomes.
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spelling doaj-art-d2c53da3deee4373a3500fed4fbdd0792025-08-20T02:38:39ZengIEEEIEEE Access2169-35362024-01-011218492918493910.1109/ACCESS.2024.351335610786023Extending the Low Frequency Limit of Tightly Coupled Dipole Arrays for Ultra-Wide Bandwidth With Ultra-Thin ProfileRajbala Solanki0https://orcid.org/0000-0003-3808-4767Peng Khiang Tan1Theng Huat Gan2https://orcid.org/0000-0002-9383-2505National University of Singapore, Queenstown, SingaporeNational University of Singapore, Queenstown, SingaporeNational University of Singapore, Queenstown, SingaporeThis paper proposes a flexible PCB based design for an ultra-wideband tightly coupled dipole array (TCDA) with an ultra-thin profile. The design approach involves increasing the capacitance between the dipole and the coupling patch, which compensates for ground inductance and effectively lowers the low frequency, thereby enhancing the bandwidth. The proposed configuration integrates a TCDA on an ultra-thin flexible PCB, a resistive frequency selective surface (FSS), and a balun (i.e. BALanced to UNbalanced feed transformation) constructed using a tapered microstrip line (MSL). By incorporating the FSS layer, ground reflection effects are effectively mitigated, leading to improved bandwidth. Additionally, the use of an ultra-thin flexible PCB (explored for the first time in TCDAs, to the best of our knowledge) allows the TCDA to extend its low frequency limit, further contributing to bandwidth enhancement. However, utilizing an ultra-thin flexible PCB poses fabrication challenges, such as maintaining uniform separation from the ground plane and difficulties with soldering etc. Numerical simulations indicate that the TCDA array achieves a bandwidth of approximately 24:1. The overall profile of the array is approximately <inline-formula> <tex-math notation="LaTeX">$\lambda _{L}$ </tex-math></inline-formula>/25, (where <inline-formula> <tex-math notation="LaTeX">$\lambda _{L}$ </tex-math></inline-formula> is the wavelength at the lowest frequency of operation) and it has an average radiation efficiency of 66%. To verify the accuracy of the simulation results, an <inline-formula> <tex-math notation="LaTeX">$8.5\times 8.5$ </tex-math></inline-formula> array prototype is fabricated and measurements are performed. The measured results closely align with the simulated outcomes.https://ieeexplore.ieee.org/document/10786023/Antennabaluncompact antennacouplingcoupling capacitancedipole antenna
spellingShingle Rajbala Solanki
Peng Khiang Tan
Theng Huat Gan
Extending the Low Frequency Limit of Tightly Coupled Dipole Arrays for Ultra-Wide Bandwidth With Ultra-Thin Profile
IEEE Access
Antenna
balun
compact antenna
coupling
coupling capacitance
dipole antenna
title Extending the Low Frequency Limit of Tightly Coupled Dipole Arrays for Ultra-Wide Bandwidth With Ultra-Thin Profile
title_full Extending the Low Frequency Limit of Tightly Coupled Dipole Arrays for Ultra-Wide Bandwidth With Ultra-Thin Profile
title_fullStr Extending the Low Frequency Limit of Tightly Coupled Dipole Arrays for Ultra-Wide Bandwidth With Ultra-Thin Profile
title_full_unstemmed Extending the Low Frequency Limit of Tightly Coupled Dipole Arrays for Ultra-Wide Bandwidth With Ultra-Thin Profile
title_short Extending the Low Frequency Limit of Tightly Coupled Dipole Arrays for Ultra-Wide Bandwidth With Ultra-Thin Profile
title_sort extending the low frequency limit of tightly coupled dipole arrays for ultra wide bandwidth with ultra thin profile
topic Antenna
balun
compact antenna
coupling
coupling capacitance
dipole antenna
url https://ieeexplore.ieee.org/document/10786023/
work_keys_str_mv AT rajbalasolanki extendingthelowfrequencylimitoftightlycoupleddipolearraysforultrawidebandwidthwithultrathinprofile
AT pengkhiangtan extendingthelowfrequencylimitoftightlycoupleddipolearraysforultrawidebandwidthwithultrathinprofile
AT thenghuatgan extendingthelowfrequencylimitoftightlycoupleddipolearraysforultrawidebandwidthwithultrathinprofile