Ontwerp en Analyse van Schoeiselantennes voor Draagbare en Lichaamsgebonden Draadloze Systemen

This doctoral research investigates the design, miniaturization, and implementation of antennas embedded in footwear for wearable and body-centric wireless communication systems. With the increasing demand for high-data-rate, low-latency wireless connectivity in applications such as health monitoring, indoor navigation, and smart wearables, footwear offers a rigid platform for integrating antennas. The work focuses on two core concepts: constructive mutual coupling and full-duplex operation. First, strongly coupled planar arrays are studied, showing that mutual coupling can be exploited to achieve maximum aperture efficiency and compact high-gain designs. This concept is extended to millimeter-wave (mm-wave) frequencies, resulting in a circularly polarized (CP) array, the first mm-wave antenna successfully integrated into footwear. Second, the thesis develops self-diplexing and full-duplex antennas capable of simultaneous transmission and reception with high port isolation and harmonic suppression. These designs are further advanced to dual-band self-duplexing structures spanning microwave and mm-wave frequencies. Finally, a self-quadruplexing antenna is presented, operating at four distinct frequency bands (5.8, 7.4, 28, and 38 GHz) using Substrate-Integrated Waveguide (SIW) techniques. Two designs are validated through simulations, fabrication, and measurements in both free-space and footwear-embedded conditions at mmwave frequencies. The results confirm wide bandwidth, high isolation, compactness, and SAR compliance, establishing practical frameworks for future wearable communication systems. The research demonstrates that compact, efficient, multi-band, and full-duplex antennas can be successfully realized in footwear, opening pathways toward next-generation gigabit-capable smart wearable platforms.