On the Decoupling of an On-Body-Matched Microwave Antenna for Head Screening

Microwave-based head screening is a challenge that requires a sensitive and responsive antenna capable of identifying, discriminating, and sensing variations in the scattering response due to internal dielectric contrast. These variations might be degraded by external interferences from other applications, sharing the frequency band and by multipath interference caused by non-through-body traveling waves, both of which limit accuracy. This paper examines the inclusion of an immediately attached back-self and inter-element absorbing foam layer, that can be a practical, low-cost, off-the-shelf solution, in an on-bodymatched-antenna array, to mitigate unwanted interferences. The study employs numerical and experimental tests and finds a suitable and industrially scalable setup. Finally, a pneumatic system is proposed as an adaptability mechanism that adjusts the antenna-to-head attachment regarding the head size, eliminating unwanted air gaps between the antenna and the head.