A Printed Wide‐Slot Antenna With Modified Tuning Stub and Parasitic Elements for Glucose Sensing Applications

ABSTRACT

This paper presents a printed wideband slot antenna, achieving bandwidth enhancement through a centered parasitic rectangular patch and a fork‐shaped tuning stub with diamond tips applicable for glucose sensing applications. Performance is further augmented by rectangular parasitic elements placed alongside the feed line. The analysis of simulation data indicates that the impedance bandwidth is significantly influenced by the geometry of three critical components: (1) the diamond‐shaped tuning stub front, (2) the parasitic patches located near the feeding point, and (3) the spacing between the feed line and these parasitic patches. Experimental results confirm the proposed antenna achieves an impedance bandwidth (−10 dB) of 256%, covering 2.4 to 16.2 GHz. For glucose sensing, a frequency shift of approximately 2.85 GHz is observed when the dielectric constant decreases from 72 to 68 (corresponding to increase glucose concentration), yielding an average sensitivity of ∼712.5 MHz per unit dielectric constant change. This broad frequency response along with dielectric variations‐based frequency shift, enabled by its capacitive properties, makes the proposed design highly suitable for glucose detection applications.