Design and characterization of a miniaturized implantable UHF RFID tag based on LTCC technology

This paper presents the design and characterization of a novel, compact, multilayer, passive UHF-RFID tag solution for implantable biotelemetry based on low-temperature co-fired ceramic (LTCC) technology. A spiral planar inverted-F antenna (PIFA) was matched to the UHF integrated circuit (IC) impedance by an inductor line. The LTCC process allowed the IC to be embedded in a sealed cavity. Simulations and measurements of the reflection coefficient and the tag range were carried out when the RFID tag was implanted in the center of a 10 cm cubic skin phantom. The dimensions of the prototype were 8×7×2 mm
³
, leading to a total volume of 112 mm
³
. Results indicated a 6 dB bandwidth of 39 MHz and 84 MHz for simulations and measurements, respectively, and a tag range of approximately 10 cm.