Sextuple-Band Circularly Polarized Shared-Aperture Antenna for Navigation and Wireless Communication

A sextuple-band circularly polarized (CP) shared-aperture antenna (SAA) with a small frequency ratio (FR) is presented in this letter. The SAA consists of a wideband scanning array and five narrowband antennas. For a high integration, the stacked, interlaced and structure-reused schemes are employed comprehensively. To solve the problem of the insufficient area of the lower antenna to support the upper antenna in a stacked scheme, the metal column is introduced, and it can also shield out the effects of feeding coaxial lines on the performance of the lower antenna. By loading the cavity, the degraded performance at the low elevation angle can be compensated. The SAA has a high ratio of aperture reduction compared with traditional multiple separate antennas, while keeping a lower profile. It can achieve two-dimensional beam steering in a scanning range of ±45°.The prototype was fabricated, and the measured results are consistent with the simulated ones. This SAA is well-suited for navigation and wireless communication.