Multiband Antenna Using Folded Inverted-F Structure

The patent employs a folded inverted-F antenna structure that transitions from a conventional planar layout to a three-dimensional folded configuration. The radiating element is folded back on itself multiple times, utilizing vertical and lateral dimensions to achieve an effective electrical length corresponding to wider bandwidth operation, while the physical footprint remains compact. This dimensional transformation allows the antenna to maintain small volume while achieving the bandwidth characteristics of a larger antenna.

The antenna structure incorporates nested folding where the radiating element is folded back within its own spatial envelope. Each fold nests part of the antenna structure within the volume occupied by previous sections, creating a compact configuration that maximizes the effective length within a minimal bounding box. This nesting approach allows the antenna to achieve wide bandwidth while maintaining a very small overall volume suitable for portable devices.

The folded inverted-F structure utilizes three-dimensional folding to maintain an effective radiating length that supports reliable signal reception across multiple frequency bands. The multiple folds create additional current paths and resonant structures that enhance the antenna's receiving capability, ensuring that compact dimensions do not compromise signal quality or reception reliability.

The radiating element is divided into multiple folded segments, each contributing to the overall receiving performance. The segmentation creates multiple interaction zones with incoming electromagnetic waves, effectively increasing the antenna's capture cross-section and improving signal reception reliability despite the compact overall size. Each segment can be optimized for specific frequency ranges within the multiband operation.

The patent resolves this contradiction by folding the inverted-F antenna structure in multiple dimensions. The radiating element is bent and folded to achieve an effective electrical length that provides wide bandwidth coverage, while the physical projection of the antenna occupies minimal space. This dimensional transformation enables the antenna to achieve the bandwidth performance of a large conventional antenna within a compact volume suitable for modern portable devices.

The nested folding configuration allows the antenna to achieve wide bandwidth by nesting the radiating element within its own spatial envelope. Each fold nests subsequent sections within the volume already occupied, creating a compact structure that maintains the electrical characteristics of a much larger antenna. This nesting approach enables wide bandwidth operation in a volume that would otherwise be insufficient for conventional antenna designs.