Dual Polarized Gain Enrichment of a Low-Cost Multi-Band Circular Fractal Antenna Using Tunable Stacked FSS for Wireless Applications

The communication presents a dual-polarized multi-band stacked-tunable frequency selective surface (S-FSS) circular-fractal monopole antenna of size 0.537 lambda 0\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\uplambda }_{0}$$\end{document} x 0.28 lambda 0\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\uplambda }_{0}$$\end{document}, (lambda 0\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\uplambda }_{0}$$\end{document} is free space wavelength at design frequency 5 GHz). An edge-feed new circular-fractal shape is used to achieve linear and circular polarization instead of using conventional diagonal feed, offset feed, and dual 90 degrees port feeding methods. The radiating patch and S-FSS are separated by a distance of 2.0 mm air gap. A novel designed double negative metamaterial unit cell (consists 4 satellite-shaped sub-cells) based 1 x 3 S-FSS was used to achieve tri-bands. The two substrates separation adjustment helps to control gain, - 10 dB bandwidth, and resonating frequencies. The S-FSS is tuned with eight PIN (BAP 64 02 V) diodes this increases the complexity of the antenna but 256 combinations of PIN diodes switching operations added an extra feature of antenna tuning flexibility without redesigning of new antennas. The measured and the simulated results of four switching combinations of PIN diodes are found in excellent match with acceptable deviation in the resonating frequencies. The proposed antenna achieves a peak gain of 8.98dBi. The introduced S-FSS leads gain enrichment from 4.22 to 8.98 dBi. Therefore, the prototyped antenna model is suitable for microwave S-band (3.56-4.63 GHz), C-band (5.17-13.22 GHz), and C-/partial X-band (6.74-8.22 GHz) applications, satellite, multiband wireless communications, short-/long-range tracking systems, radar systems, Wireless LAN security and interference extenuating, for beam steering, band selection, absorber, antenna radomes.