Small-Size Wearable High-Efficiency TAG Antenna for UHF RFID of People

This paper introduces a small-size, low-profile wearable radiator based on the coupled patches and vertically folded patches techniques for application as a tag antenna for identification of people in the European UHF RFID band. The electric field distribution comes out dominantly from the central coupling slot, and thus the electric properties of the radiator are almost unaffected by the human body to which the antenna is intended to be attached. Accordingly, with the relative size 0.14×0.12×0.009 λ0 at 866 MHz (50×40×3.04 mm3), the antenna exhibits total efficiency better than 50%, even if it is attached directly to a person

Obrazovanje na području antena, rasprostiranja valova i mikrovalova

The paper is focused on teaching of »applied microwaves«. Attention is turned to antennas, but the same structure of education process is possible to apply for e.g. radio-wave propagation, microwaves, EMC, and other »electromagnetic topics« in their whole. The structure of the education is based on the appropriate amount of the theory followed by the computer simulations, the theoretical and engineering design and development, the measurement and final evaluation, which acts as the feedback between the initial goals and the final results. Important role of laboratory experiments based on flexible experimental set-ups is introduced and the possibility of distant (internet) laboratory excess is mentioned.Rad je usredotočen na učenje »primijenjenih mikrovalova«. Pozornost je okrenuta antenama, ali se ista struktura obrazovnog procesa može primijeniti na rasprostiranje radijskih valova, mikrovalove, elektromagnetsku kompatibilnost i druge elektromagnetske sadržaje. Struktura obrazovanja osniva se na odgovarajućoj teoriji popraćenoj simulacijama na računalu, teorijskom i inženjerskim proračunima i razvoju, mjerenjima i konačnoj provjeri, koja djeluje kao povratna veza između početnih ciljeva i konačnih rezultata. Utvrđena je važna uloga laboratorijskih eksperimenata temeljenih na fleksibilnim eksperimentalnim modelima i spomenuta mogućnost učenja na daljinu

Illustration of the Impedance Behaviour of Extremely Low-Profile Coupled Shorted-Patches Antennas for UHF RFID of People

The recently introduced coupled shorted-patches technique for the design of extremely low-profile UHF RFID tag antennas is used to illustrate the flexibility of selected feeding methods for tuning the antenna input impedance for the complex values required for matching with typical RFID chips. We present parametric studies of the impedance behaviour of dipole-excited and directly excited antennas designed for radiofrequency identification of people in the European UHF frequency band. Our study can significantly facilitate the design of this class of on-body tag antennas

Constraints of Using Conductive Screen-Printing for Chipless RFID Tags with Enhanced RCS Response

The analysis and experimental verification of the properties of four types of chipless RFID tags with an increased RCS response level designed and fabricated by conductive screen-printing using silver paste on foil and paper substrates was performed. The analytical formula for the quality factor of microstrip structures with a reduced conductivity of the metal layers was used to predict the changes and detectability of the backscattered RCS response. The analysis provides insight into the limitations and outlines the possibilities of chipless structures screen-printed on foil and paper substrates, which can be of significant benefit to further reducing the cost, and to speed up the production of these tags for identification and sensing purposes

Influence of Mutual Coupling on Stability of RCS Response in Chipless RFID

The paper investigates the influence of mutual coupling between individual scatterings of chipless Radio Frequency Identification (RFID) tags based on its frequency-domain performance using a simplified equivalent circuit model. The proposed steady state analysis predicts a fast and satisfactory amplitude level and frequency position of resonant peaks of a predicted radar cross section (RCS) response. The proposed approach is capable of pre-evaluating a suitability of the particular scattered topology for implementing in chipless RFID tags. It is demonstrated on two different geometries