Three Polarization MIMO Antenna With Hierarchical Substrate Stacking

The patent implements a nested structure where multiple radiation elements (first, second, and third radiation parts) are arranged in hierarchical layers within a compact substrate. The first radiation part is on a first substrate, the second radiation part is on a second substrate that is partially or fully overlaid on the first substrate, and the third radiation part is on a third substrate that is partially or fully overlaid on the second substrate. This nesting approach enables three polarization MIMO functionality while significantly reducing the overall antenna volume compared to conventional distributed arrangements.

The patent transitions from planar two-dimensional antenna layouts to three-dimensional hierarchical structures by stacking multiple radiation substrates vertically. The feed parts extend through multiple substrates in the vertical dimension, creating intercoupling paths that enable three polarization functionality (x-polarization, y-polarization, and z-polarization) within a compact footprint. This dimensional transition allows the antenna to achieve enhanced channel capacity without proportional increases in volume.

The patent divides the antenna system into multiple independent but interconnected modules: first, second, and third radiation parts on separate substrates, each with its own feed parts. These segmented modules can be manufactured independently using standard PCB fabrication techniques and then assembled by stacking the substrates with appropriate spacing. This segmentation enables modular manufacturing, reducing overall fabrication complexity and cost compared to creating a monolithic three-polarization antenna structure.

The patent designs the radiation parts and feed parts to serve multiple functions simultaneously. Each radiation part can support multiple polarization modes, and the feed parts are configured to excite different polarization components through strategic positioning and orientation. This multi-functionality reduces the total number of separate components needed, thereby lowering fabrication costs while maintaining high transmission efficiency across all three polarization channels.

The patent employs ground planes with non-uniform ground structures that provide localized electromagnetic shielding between the stacked radiation substrates. The ground planes are positioned between adjacent radiation substrates and feature strategically designed ground patterns that create electromagnetic isolation zones. This local quality enhancement ensures that each radiation part maintains independent channel characteristics despite the compact vertical stacking, preserving electromagnetic isolation while achieving volume reduction.

The patent introduces ground planes as intermediary elements between the stacked radiation substrates. These ground planes serve as electromagnetic mediators that isolate the electric fields of adjacent radiation parts while allowing controlled coupling for feed signal transmission. The ground planes with their specific ground patterns act as barriers that prevent unwanted electromagnetic interference between channels, maintaining reliability in the compact three-polarization structure.