A Shorted Stub Loaded UWB Flexible Antenna for Small IoT Devices

Area of Science:

• Electrical Engineering
• Electromagnetics
• Antenna Design

Background:

• Ultra-Wideband (UWB) technology requires antennas with broad operational bandwidth.
• Existing UWB antennas often lack compactness and flexibility for integration into modern electronic devices.
• The development of miniaturized and adaptable antenna solutions is crucial for portable and wearable electronics.

Purpose of the Study:

• To design and demonstrate a compact, geometrically simple Ultra-Wideband (UWB) antenna.
• To achieve a wide operational bandwidth covering the globally allocated UWB spectrum.
• To ensure stable antenna performance under flexible and conformal conditions for integration into electronic devices.

Main Methods:

• Utilized a flexible ROGERS 5880 substrate (0.254 mm thickness) for antenna fabrication.
• Modified a traditional rectangular monopole antenna by incorporating triangular slots and a semi-circular stub.
• Optimized the antenna design to achieve desired impedance bandwidth and operational frequency range.
• Conducted flexibility analysis by bending the antenna along the x and y axes.

Main Results:

• Achieved an Ultra-Wideband (UWB) range from 2.73 GHz to 9.68 GHz, covering the global UWB spectrum.
• The antenna exhibits a compact size of 15 × 20 mm², suitable for integration into small electronics.
• Demonstrated stable performance in terms of return loss, radiation pattern, and gain under both rigid and bent (conformal) conditions.
• Validated results through strong agreement between simulated and measured data for rigid and bent configurations.

Conclusions:

• The proposed compact and flexible UWB antenna meets the requirements for UWB applications.
• Its stable performance in bent states makes it suitable for conformal integration into flexible devices.
• The antenna represents a significant advancement for current and future compact-sized flexible electronic systems.