Textile Bandwidth-Enhanced Half-Mode Substrate-Integrated Cavity Antenna Based on Embroidered Shorting Vias

Area of Science:

• Electromagnetic Engineering
• Textile Antennas
• Wearable Technology

Background:

• Substrate-integrated cavity antennas offer potential for miniaturization and integration.
• Existing designs often lack sufficient bandwidth and flexibility for wearable applications.
• The 5 GHz wireless local area network (WLAN) band requires antennas with wide operational bandwidths.

Purpose of the Study:

• To design and fabricate a bandwidth-enhanced half-mode substrate-integrated cavity (HMSIC) antenna for textile applications.
• To improve the fractional bandwidth of HMSIC antennas using embroidered shorting vias.
• To evaluate the antenna's performance, including impedance bandwidth, radiation efficiency, gain, and robustness in proximity to human tissues and under bending conditions.

Main Methods:

• Design of a textile HMSIC antenna incorporating embroidered hollow posts as shorting vias.
• Utilizing computerized embroidery techniques for prototype fabrication.
• Simulations and measurements to assess antenna performance, including S-parameters, radiation patterns, and specific absorption rate (SAR).

Main Results:

• Achieved an expanded -10 dB impedance bandwidth of 4.87–6.17 GHz (23.5% fractional bandwidth), covering the 5 GHz WLAN band.
• Simulated radiation efficiency exceeded 97% with a maximum gain of 7.6 dBi.
• Demonstrated robust frequency response near human tissues and under bending conditions, with simulations confirming electromagnetic safety (SAR).

Conclusions:

• The proposed textile HMSIC antenna with embroidered shorting vias effectively enhances bandwidth for wearable 5 GHz WLAN systems.
• The antenna exhibits excellent performance metrics and maintains robustness in realistic usage scenarios.
• The design is suitable for electromagnetic safety-critical applications involving human interaction.