Multi-Band mm-Wave Wearable Antenna Synthesized with a Genetic Algorithm

Abstract

This paper presents the design of a novel fabric-based multi-band microstrip antenna in mm-wave frequencies for wearable applications. The reference patch antenna was etched on a flexible polytetrafluoroethylene (PTFE) fabric substrate with an overall dimension of 18 mm × 18 mm × 0.6 mm and optimized the patch geometry using a binary-coded genetic algorithm. The algorithm iteratively creates a new shape of the path surface, evaluates the cost function, and returns the best-fitted geometry based on the formulated fitness function. The free space and on-body simulation of the best-fitted antenna performance parameter was investigated and analyzed. In free space, the proposed antenna is resonant at five distinct frequencies: 27.8 GHz, 30.3 GHz, 40.1 GHz, 47.2 GHz, and 56.7 GHz. The antenna achieves a wide bandwidth of 0.69, 2.32, 2.22, 1.76, and 8.11 GHz and an improved broadside directivity of 10.3, 8.5, 7.8, 9.6, and 8.9 dB in free space, respectively. For on-body analysis, the antenna was simulated using a three-layer human body phantom model at three distinct distances. The gain and radiation efficiency were significantly reduced when the antenna was close to the phantom model and gradually enhanced as the gap increased. Moreover, the antenna performances were evaluated and compared by using four additional fabric substrates. Because of its excellent on-body performance with flexible textile-based substrates, the optimized antenna is a suitable candidate for multi-band body-centric communications.

Miniaturized novel quintuple-band microstrip patch antenna for K-band application

“…Pentaband operation is realized in sub-10 GHz frequency range, maintaining a size of 27.4×24 mm². Another work on K band mm wave antenna with designed dimension of 4.46 mm × 6.6 mm with RT Duroid substrate having resonant frequencies spread over 27 GHz to 57 GHz, has gain varying from 7.7 dBi to 10.2 dBi [50]. A three-band resonant frequency (28 GHz, 40 GHz and 47 GHz), antenna using FR4 epoxy dielectric material has gain of 5.64 dBi to 8.7 dBi [51].…”

A Survey – Wearable Antenna Techniques and its Applications

“…Dejen et al [15] designed a multi-band microstrip antenna at mm-wave frequencies for use as a wearable antenna. The patch antenna was built on a flexible polytetrafluoroethylene fabric substrate with dimensions and the patch shape was optimised using a binary coded evolutionary algorithm.…”