Opportunity
This patent presents an ultra-wideband (UWB) loop antenna designed to circumvent the fundamental bandwidth-size trade-off. Unlike conventional loop antennas where each order (1λ, 2λ, 3λ…, λ: wavelength) has only one single mode/resonance, the proposed design exploits multi-order dual-degenerate modes. The primary innovation lies in the integration of an equivalent capacitive coupling element (eCCE) positioned near the feeding port. This structure introduces a perturbation that excites and splits the resonant frequencies of the dual-degenerate modes at each order. Consequently, it enables the excitation of multiple closely-spaced resonances—up to 2n resonances for the n orders—resulting in an ultra-wideband response. The antenna has a reflection coefficient below -10 dB across the 0.73-7.10 GHz, achieving an absolute bandwidth of 6.37 GHz and a fractional bandwidth of 163%, with a total efficiency exceeding 64%. At its lowest operating frequency, the loop circumference corresponds to 1λ, with a physical diameter of 9.6 cm, making it ideal to integrate into the frames or housings of Unmanned Aerial Vehicles (UAVs) and foldable smartphones. Furthermore, a miniaturized folded version tailored for smartwatch form factors (4.4 × 2.8 × 0.5 cm) delivers a -6 dB bandwidth from 1.74 to 8.87 GHz (134% bandwidth), significantly surpassing state-of-the-art smartwatch antennas in literature, while maintaining a total efficiency above 66 %. This invention eliminates the need for complex matching networks and expensive antenna tuners, thereby streamlining the design, tuning, and manufacturing processes.
Technology
The innovation involves a one-step electrospinning process that produces a monolayer fiber membrane with spatially controlled hydrophobicity and hydrophilicity. Initially, a flexible substrate, such as gauze, is coated with superhydrophobic particles like SiO₂ aerogel and attached to a negatively charged electrospinning drum. A viscous spinning solution is then prepared by mixing superhydrophilic particles such as microcrystalline cellulose, polymers like polyurethane, and metal salts like LiCl in organic solvents. During electrospinning, the solution is sprayed onto the substrate under high voltage (16–26 kV), resulting in a monolayer where superhydrophobic particles adhere to one side via electrostatic forces, while the other side remains superhydrophilic due to embedded hydrophilic particles. The membrane's asymmetry is due to differential particle distribution during fiber formation, with hydrophobic particles anchored to the substrate-facing side by nanofiber adhesion, while hydrophilic components dominate the air-facing side. This design ensures unidirectional moisture transport (18.5 kg/m²/day from hydrophobic to hydrophilic side versus 12.8 kg/m²/day in reverse) without the risk of delamination.
Advantages
- Achieve ultrawideband performance with the entire sub-6 GHz frequency range
- Compact and low-profile, and can be further folded to reduce the overall footprint
- Eliminate the need for costly and complex antenna tuners, reducing bill-of-materials (BOM) cost and simplifying antenna design.
- Provide interference robustness and frequency deviation tolerance enabled by the ultrawideband property.
- Facilitate bezel-style integration into mobile devices.
Applications
- Smartphones, smartwatches, smart glasses, and tablets requiring multiband connectivity across cellular networks (from 2G to B5G/6G), as well as Wi-Fi, Bluetooth, and GNSS.
- UAVs for communication and telemetry.
- Ultrawideband wireless energy-harvesting systems for powering low-power electronic devices.
- Ultrawideband sensing applications in healthcare, environmental monitoring, and security.
- Automotive telematics and vehicle-to-everything (V2X) communication systems.
- Portable medical devices and remote monitoring equipment.
