摘要 : This article presents a novel broadband circularly polarized microstrip array antenna for synthetic aperture radar system onboard Cessna 172 Aircraft. The antenna employs an <inline-formula> <tex-math notation="LaTeX">$8\times 8$ ... 展开 This article presents a novel broadband circularly polarized microstrip array antenna for synthetic aperture radar system onboard Cessna 172 Aircraft. The antenna employs an <inline-formula> <tex-math notation="LaTeX">$8\times 8$ </tex-math></inline-formula> matrix formation with uniform element separation of <inline-formula> <tex-math notation="LaTeX">$0.5\lambda $ </tex-math></inline-formula> and single-proximity-coupled strip-line feeding. The circular polarization wave generation uses a curved-truncation patch and a circle-slotted parasitic patch above it to realize the broadband circularly polarized antenna. The broadening of the axial ratio bandwidth (ARBW) applies a fully serial sequential rotation on the array feeding network. Meanwhile, the gain is improved using a circle-slotted parasitic patch with a floating cover on the top layer. The prototype antenna has a physical aperture of 270 mm <inline-formula> <tex-math notation="LaTeX">$\times $ </tex-math></inline-formula> 300 mm with 1.1-kg weight. The prototype produces an impedance bandwidth of 1.5 GHz (29.3%), ARBW of 1.62 GHz (30.6%), a gain of 18.17 dBic, and aperture efficiency of 26%. The azimuth and elevation beamwidth achieved 12.7° and 13.0° at the center frequency, respectively. 收起