Miniaturization of a microstrip antenna with magneto-dielectrics substrates for a passive tag RFID operating at 915 MHz on a metallic surface

This article presents the miniaturization process of a rectangular patch RFID antenna. Based on an RFID antenna which is produced to be used on metal surfaces, a smaller antenna compatible with the Impinj Monza 4E chip was designed. In order to match the impedance of the chip, while maintaining a closer performance of the original antenna at 915 MHz, a magneto-dielectric substrate was used and a simulation was done using the CST MicroWave Studio® electromagnetic simulation tool. Moreover, the new design considers the factor of miniaturization in function of the intrinsic properties of the used substrate. Results show that a simple design was constructed and that was tuned to the desired frequency, matching the impedance of the chip.