A Bra Monitoring System Using a Miniaturized Wearable Ultra-Wideband MIMO Antenna for Breast Cancer Imaging

Abstract

This paper represents a miniaturized, dual-polarized, multiple input–multiple output (MIMO) wearable antenna. A vertically polarized, leaf-shaped antenna and a horizontally polarized, tree-shaped antenna are designed, and the performance of each antenna is investigated. After designing the MIMO antenna, it is loaded with stubs, parasitic spiral, and shorting pins to reduce the coupling effects and remove the unwanted resonances. Afterward, the two-port MIMO cells are spaced by 2 mm and rotated by 90° to create three more cells. The antennas are designed using two layers of denim and felt substrates with dielectric constants of 1.2 and 1.8, and thicknesses of 0.5 mm and 0.9 mm, respectively, along with the ShieldIt™ conductive textile. The antenna covers a bandwidth of 4.8–30 GHz when the specific absorption rate (SAR) meets the 1 g and 10 g standards. Isolation greater than 18 dB was obtained and mutual coupling was reduced after integrating shorting pins and spiral parasitic loadings. A maximum radiation efficiency and directive gain of 96% and 5.72 dBi were obtained, respectively, with the relatively small size of 11 × 11 × 1.4 mm3 for the single element and final dimensions of 24 × 24 × 1.4 mm3 for the full assembly. The antenna’s performance was examined for both on-body (breast) and free space conditions using near-field microwave imaging. The achieved results such as high fidelity, low SAR, and accuracy in localization of the tumour indicate that the MIMO antenna is a decent candidate for breast cancer imaging.

A Miniaturized Full-Ground Dual-Band MIMO Spiral Button Wearable Antenna for 5G and Sub-6 GHz Communications

“…Additionally, it includes the capacitances connected to the gaps in the split rings. [ 60 ] contains all of the equations for the total capacitance C .T. and inductance LT. For the more extensive and two smaller SRRs, the resonant frequencies (f r ) are 3.4 GHz and 5.6 GHz, respectively [ 61 ].…”

Radio frequency sensing and its innovative applications in diverse sectors: A comprehensive study

“…A wearable, compact, dual-polarized, multiple-inputmultiple-output (MIMO) antenna is proposed by Mahmood et al (2021). It has a bandwidth of 4.8-30 GHz with a maximum radiation efficiency and directional gain of 96% and 5.72 dBi, respectively.…”

Circularly Polarized Textile Sensors for Microwave-Based Smart Bra Monitoring System

“…WBANs help in monitoring physiological behavior patterns in humans and studying disease prevention and control [ 1 ]. The WBAN’s ultra-lightweight, wearable sensors can be either off-body or on-body [ 2 ] and could be operated in MIMO systems [ 3 , 4 , 5 ]. Numerous applications of WBANs have embraced several devices on a large scale, including brain recording, glucose monitoring, intracranial pressure monitoring, as well as breast cancer detection [ 2 , 6 ].…”