A Reconfigurable Dual-Polarization Slot-Ring Antenna Element With Wide Bandwidth for Array Applications

• Published in: IEEE transactions on antennas and propagation Vol. 66; no. 11; pp. 5943 - 5954
• Main Authors: Shirazi, Mahmoud, Li, Tianjiao, Huang, Junyi, Gong, Xun
• Format: Journal Article
• Language: English
• Published: New York IEEE 01-11-2018; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Antenna arrays; Antennas; Bandwidth; Bandwidths; Broadband; Broadband antennas; C band; Dual polarization (waves); fractal antennas; Fractals; Frequencies; PIN photodiodes; reconfigurable antennas; Reconfiguration; Slot antennas; Superhigh frequencies; Switches; Switching; ultra-wideband (UWB) antennas; Unit cell
• ISSN: 0018-926X; 1558-2221
• DOI: 10.1109/TAP.2018.2863110

A reconfigurable dual-polarized slot-ring antenna/array, switching between S- and C-band with wide bandwidth in each operating state is presented. By simultaneously switching eight p-i-n diode switches, a <inline-formula> <tex-math notation="LaTeX">2 \times 2 </tex-math></inline-formula> C-band antenna array can be reconfigured to an S-band antenna unit cell, and vice versa. Fractal shapes are incorporated into the antenna structure to significantly enhance bandwidth. In the S-/C-band operating state, this antenna shows 69.1%/58.3% fractional bandwidth with a measured maximum realized gain of 2.4/3.1 dBi. For the <inline-formula> <tex-math notation="LaTeX">2 \times 2 </tex-math></inline-formula> C-band array, the spacing between the elements is less than <inline-formula> <tex-math notation="LaTeX">0.5\lambda _{{0}} </tex-math></inline-formula> over the frequency band which enables grating-lobe-free beam scanning. A unidirectional version of this antenna/array with more than 12/16 dB front-to-back ratio at 3.5/8 GHz is also demonstrated. This wideband antenna/array can be used as a unit cell of a larger array with element spacing of half wavelength at the center frequency of both frequency bands.