Tunable Platform Tolerant Antenna Design for RFID and IoT Applications Using Characteristic Mode Analysis

Abstract

Radio frequency identification (RFID) is a key technology to realize IoT (Internet of Things) dreams. RFID technology has been emerging in sensing, identification, tracking, and localization of goods. In order to tag a huge number of things, it is cost-effective to use one RFID antenna for tagging different things. Therefore, in this paper a platform tolerant RFID tag antenna with tunable capability is proposed. The proposed tag antenna is designed and optimized using characteristic mode analysis (CMA). Moreover, this tag antenna consists of a folded patch wrapped around FR 4 substrate and a feeding loop element printed on a paper substrate. The inductive feeding loop is stacked over folded patch and it provides impedance match with RFID chip. Because of separate radiating and feeding element, this tag antenna has a versatility of impedance matching with any RFID chip. Furthermore, this tag is able to cover American RFID band (902–928 MHz) and can be tuned to European RFID band (865–868 MHz) by adding tunable strips. In order to demonstrate platform tolerant operation, the read range of RFID tag is measured by mounting it on different materials. The maximum read range of RFID tag is 4.5 m in free space or on dielectrics and 6.5 m above 200 × 200 mm2 metal plate, respectively.

Planar Pyramid Shaped UHF RFID Tag Antenna With Polarisation Diversity for IoT Applications Using Characteristics Mode Analysis

“…The Impinj Monza 4 D chip is connected among all four terminals of tag antenna, as mentioned in the datasheet. To corroborate the performance of the antenna, the input impedance of this dual polarised tag has been measured by following the procedure expressed in [38] and [25] using Agilent E8363B vector network analyser. Two coaxial cables were employed for impedance and return loss measurement, with outer coats of coaxial cables are soldered together.…”

“…Moreover, the total far-fields associated with total induced currents can also be determined as follows [25]:…”

Low-Cost Inkjet-Printed RFID Tag Antenna Design for Remote Healthcare Applications

“…This setup provides a more accurate measure of read range. It estimates the read range with a smaller value of EIRP (equivalent isotropic radiated power) at a fixed distance, provided by foam spacer, then calculate the maximum theoretical read range using formula given in [34]. Fig.…”

Orientation insensitive UHF RFID Tag Antenna with polarization diversity using Characteristic Mode Analysis

“…The most of conventional and commercial tags are consists of dipole type structures posing a linear polarization, which further leads to orientation sensitivity and quasi-omnidirectional radiation pattern. Usually, the RFID system employs a circularly polarized reader antenna to solve the orientation sensitivity problem at the expense of 3 dB loss due to polarization mismatch between the reader antenna and tag [1]- [2]. In [3], a dual polarized PIFA based RFID tag antenna was proposed to solve the orientation problem, however, the design has large dimensions 64 x 64 x 2 mm3.…”

“…The mode 1 has an asymmetric current distribution which results in the cancelation of the field in the + z direction. However, the mode pairs (2,4) and (3,4) can be exploited to achieve polarization diversity. The tag parameters are optimized further using CST Microwave studio to get a conjugate match with Impinj Monza 4 D RFID chip with impedance 11-143j @ 915 MHz.…”