Details

Autor(en) / Beteiligte

• Qiu, Lei-Lei
• Zhu, Lei
• Xu, Yanhui

Titel

Wideband Low-Profile Circularly Polarized Patch Antenna Using 90° Modified Schiffman Phase Shifter and Meandering Microstrip Feed

Ist Teil von

• IEEE transactions on antennas and propagation, 2020-07, Vol.68 (7), p.5680-5685

Ort / Verlag

New York: IEEE

Erscheinungsjahr

2020

Quelle

IEL

Beschreibungen/Notizen

• This communication proposes a wideband low-profile circularly polarized patch antenna based on a broadband 90° modified Schiffman phase shifter and a meandering L-shaped microstrip feed. The whole antenna consists of a broadband hybrid feeding network and a circular patch radiator. The hybrid network has two branches that operate in the first and second Schiffman periods, and thus can achieve 113% 10 dB return loss bandwidth and 75% phase shift bandwidth within 90°± 4.6° under a relaxed coupling strength of 1.58. To reduce the profile, the planar microstrip L-shaped feeding probe is properly meandered, which provides not only broadband impedance matching, but also an extra degree of freedom in the reduction of cross polarization, thus achieving a wide axial ratio (AR) bandwidth. Simulated and measured results show that the antenna has indeed achieved a low profile (<inline-formula> <tex-math notation="LaTeX">0.05~\lambda _{0} </tex-math></inline-formula>) with 50.5% impedance bandwidth, 47.8%AR bandwidth, and 34% gain bandwidth (>3 dBi).