Structure Reuse for Scanning Angle Extension and Decoupling in Shared Aperture Antenna Array for Base Station Applications

A shared aperture array with structure-reuse scheme for inter-array decoupling and array scanning angle extension is proposed. This array consists of a low-band (LB) array interleaved with a high-band (HB) array, maintaining an inter-element distance of 0.4λ₀ at both LB and HB. Furthermore, the HB array elements function as artificial magnetic conductors (AMCs), exhibiting a reflection coefficient phase of 0° within the operational band of the LB array. This configuration allows the LB array elements to achieve a wide beam scanning angle. To mitigate the blockage effect caused by the LB elements on the HB array, back-to-back sprit resonant rings (SRRs) are incorporated onto the LB dipole arms to suppress scattering within the HB frequency range. The cross-band coupling is reduced from -18.5 dB to -23.5 dB over the HB frequency. The cross-band coupling of the shared aperture array is reduced lower than -19.6 dB. The interleaved 16×4 HB and 6×1 LB shared aperture array has been fabricated and measured. The simulated and measured results indicate that the proposed array achieves a 3 dBi drop-off beam scanning angle of ±71°. Simultaneously, the radiation patterns of the LB and HB elements remain largely unaffected. The proposed shared aperture array demonstrates significant advantages for multiband base station applications.