Feb 2024- Dec 2024
Role: Main Engineer / Designer
Overview:
This project aims to
- Create a compact and flexible ultra-wideband (UWB) antenna optimized for wearable and space-constrained applications.
- Design targets a wide impedance bandwidth (3.2–8.7 GHz), high radiation efficiency, and mechanical flexibility, making it suitable for next-generation localization and communication systems.
📐 Design Method:
1. Conventional Bell-shape challenges
- Started with a traditional bell-shaped monopole prototype (problem with mid-band frequency highlighted in yellow)
- Reducing the width of the antenn (18 mm to 12 mm) mismatch in the mid-band frequency
- Cannot miniturize furtur in with just elliptical or circular geometry
2. Impelmentation Wineglass shape with Bezier Curve
- Beizer curve for more adaptive and smooth strucutre as shown below.
- Pushing the ground plane closer to the radaitor moved the second resonent closer to the lower frequency.
- In creasing the surface coupling between the radiator and ground, improve the matching in mid-band frequency.
- How about the high-band frequency ?
3. Trident feed
- Added trident feed to improve high-frequency performance
- Moving the parameter t shifts the second resonance to a higher frequency while maintaining the midband below -10 dB.
4. Final design
- Final parameters and dimensions are shown in the figure below.
- Fabricated on polyimide thin-film (total thickness: 125 μm) for flexibility:
🏁 Result & Achievement:
-
Operating bandwidth: 3.2 GHz to 8.7 GHz (2.7:1 ratio)
-
Consistent >70% radiation efficiency with omnidirectional pattern
-
Ultra-compact size: 35 × 12.4 × 0.125 mm³ (~0.37λ₀ × 0.13λ₀ × 0.0013λ₀)
-
Measurement confirmed simulation accuracy
Conference:
Ly, C.; Chung, J.-Y. A compact UWB Thin-film antenna design on a spline curve and Trident Feed. KIEES Summer Conference 2024
Journal:
Ly, C.; Chung, J.-Y. A Trident-Fed Wine Glass UWB Antenna Based on Bézier Curve Optimization. Electronics 2025, 14, 2560. https://doi.org/10.3390/electronics14132560
