Dual-Band Dual-Polarized Array Based on Electromagnetic Transparent Antenna for Vehicle-Mounted Base Station Systems

This paper introduces a novel ±45° shared-aperture, dual-band, dual-polarized interleaved array for vehicle-mounted base station systems. The array integrates a lower band (LB) antenna with four higher band (HB) antennas. To address the issue of cross-band scattering and its impact on higher band performance, we employ an innovative method that involves reducing the aperture size and incorporating lumped or distributed inductors. These inductors function as frequency-selective structures, permitting low-frequency currents to pass while blocking high-frequency currents. Consequently, at high frequencies, these inductors act as open circuits, making the low-frequency antenna radiator resemble multiple discontinuous small metal strips. This approach achieves an electromagnetic transparent (EMT) bandwidth of over 82.9%, making it highly suitable for mobile base station applications. By integrating this low-scattering LB antenna with four bandwidth-optimized cross dipoles, we achieve a dual-band interleaved array. The measured results confirm that the dual-band array operates effectively within the 0.85-0.98 GHz and 1.4-2.7 GHz frequency ranges, maintaining stable radiation performance. The superior performance of this design makes it an ideal choice for vehicle-based base stations.