Design and Experimental Validation of Compact NFC Antenna and Embedded SiP RFID Module Based on LTCC and PCB Technologies

This paper presents the design, fabrication, and experimental validation of compact NFC antenna structures and a miniaturized RFID module based on System-in-Package (SiP) integration. Planar spiral antennas operating at 13.56 MHz are implemented on LTCC and PCB substrates using two-layer and three-layer configurations. The influence of substrate material, geometry, and tuning strategy on inductance, resonance frequency, reflection coefficient, and Q-factor is experimentally evaluated using vector network analysis. A compact RFID module is subsequently realized using a cavity-based SiP architecture with face-down chip integration and anisotropic conductive film (ACF) interconnection. The results demonstrate that substrate selection and integration strategy significantly affect electrical performance, coupling efficiency, and miniaturization limits, providing a practical basis for the development of embedded SiP RFID/NFC modules.