Low-Profile Planar Ultrawideband Modular Antenna Array Loaded With Parasitic Metal Strips

• Published in: IEEE transactions on antennas and propagation Vol. 71; no. 7; pp. 5805 - 5816
• Main Authors: Wang, Haotong, Qu, Shi-Wei, Yang, Shiwen, Hu, Jun
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.07.2023; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Antenna arrays; Bandwidth; Dielectrics; Dipoles; Dual polarization (waves); Frequency analysis; Ground plane; Impedance matching; Loading; Low profile; Mathematical analysis; Metal strips; metasurface; Parasitic elements (antennas); Phased arrays; Resonant frequency; Surface impedance; Surface waves; Ultrawideband; ultrawideband phased arrays; Voltage standing wave ratios
• ISSN: 0018-926X; 1558-2221
• DOI: 10.1109/TAP.2023.3277217

A low-profile dual-polarized planar ultrawideband modular antenna (PUMA) array is proposed in this article. The overall profile is as small as 11.4 mm (<inline-formula> <tex-math notation="LaTeX">0.228\lambda _{high} </tex-math></inline-formula>, where <inline-formula> <tex-math notation="LaTeX">\lambda _{high} </tex-math></inline-formula> is the free-space wavelength at the highest operating frequency) based on element sizes <inline-formula> <tex-math notation="LaTeX">25\times25 </tex-math></inline-formula> mm 2 (<inline-formula> <tex-math notation="LaTeX">0.5\times 0.5\lambda _{high}^{2} </tex-math></inline-formula>) and a large operating frequency bandwidth achieved by loading lossless parasitic metal strips between the dipole patches and the ground plane. The loop-mode resonance that causes deterioration of the port isolation around the lowest operating frequency is comprehensively analyzed and suppression methods are proposed. To further reduce the overall profile, a metasurface-based wide-angle impedance matching (MS-WAIM) layer is introduced. The surface waves guided by the MS-WAIM layer during wide-angle scanning in H-plane are suppressed by cutting properly-sized square holes at critical positions. The calculated results show that the proposed infinite array can scan up to ±60° in E-/H-planes with active voltage standing wave ratios (VSWRs) below 2.9 within 2-6 GHz and orthogonal port isolations beyond 20 dB. A <inline-formula> <tex-math notation="LaTeX">12\times11 </tex-math></inline-formula> array prototype is fabricated and reasonable agreement is achieved between the calculated and measured results.