Design of a Wideband Spring Textile Antenna for Wearable 5G and IoT Applications Using Characteristic Mode Analysis

This paper presents the design and practical implementation of a wideband spring textile (WST) antenna for wearable communications. The antenna is designed on a felt substrate having a compact dimension of 32 x 42 x 3 mm(3) (0.38 lambda(g) x 0.5 lambda(g) x 0.036 lambda(g)). This antenna operates in the 3.14 to 5.45 GHz frequency range, has a bandwidth (BW) of around 2306 MHz, and has a peak realized gain of 6 dBi at 3.5 GHz. Due to a broad frequency coverage, this antenna can be used in a wide range of wireless applications, including 5G and IoT. The proposed design is analyzed in terms of reflection coefficient, radiation pattern, efficiency, gain, and surface current. Using the same electromagnetic simulation software, both characteristic mode analysis (CMA) and the method of moments (MoM) are applied in the design process. The simulated results on a human chest phantom demonstrate the -10-dB impedance bandwidths of 1461 MHz. The antenna prototype is fabricated for verification, and the simulated and measured results demonstrate that the proposed antenna is suitable for wideband on-body applications given its low-profile implementation and mechanical flexibility.