A Tri-elliptic Shaped Microstrip Patch UWB Antenna for Chipless RFID Tags

This article presents a tri-elliptic microstrip patch antenna for ultra-wide band (UWB) chipless RFID (CRFID) applications.The simple and compact structure consists of three elliptical patches that are optimized for bandwidth (BW) enhancement.The antenna is fabricated on a Rogers RT 5880 substrate with a compact size of 36.828mm 2 and has a partial ground plane (PGP) for wideband response.Both simulation and experimental results show a good agreement, hence confirming its high efficiency and omnidirectional radiation characteristics.It operates in the UWB frequency band from 3.67 to 10.5 GHz, showing a measured VSWR < 2 bandwidth of 6.83 GHz, a peak realized gain of 5.4 dBi, and a radiation efficiency greater than 94%.Further, the gain-to-aperture ratio (GAR) is calculated.It is found that the proposed antenna outperforms most of the existing CRFID tag antennas with 0.52 dBi/cm 2 .In addition, the antenna is tested in anechoic chamber and different multipath line of sight (LOS) scenarios for far field radiation pattern and wireless communication validation.Moreover, the antenna is attached with a 9-bit truncated-C multi-resonator (TCMR) to demonstrate its capabilities of encoding and decoding a wireless bit sequence of 'All Present' (111111111) even in the presence of path loss and attenuation.With proper implementation and adaptation to innovative and wearable technologies, this proposed design can become a foundational model for a suitable candidate in logistics, healthcare, and wearable applications, providing a reliable solution for next-generation UWB CRFID systems.