A review on wireless sensors fabricated using the low temperature co-fired ceramic (LTCC) technology

In recent years, with the development of wireless communication systems and intelligent auxiliary equipment, the development of various wireless sensors has attracted more and more scientific and commercial attention. A new type of LC (Lenz (inductor)–Capacitor) wireless sensor was designed and fabricated using Low Temperature Co-fired Ceramics (LTCC) technology, including the advantages of low-cost wireless sensing of radio frequency (RF) communications and high operating temperature, miniaturisation, low weight, excellent thermal management, and multilayer printed circuit board of LTCC technology. LTCC technology offers functionalities such as high/low permittivity, low dielectric loss in a single multilayer package and multi-functional features by integration and interconnections. It also offers the highest interconnect density for the fabrication of 3D structures with multilayer additive fabrication of ceramic 2D sheets. In this article, an introduction to the LTCC technology and the mechanism of LC resonance wireless interrogation are overviewed. Then, we summarise the latest developments in wirelessgas, pressure, proximity and microfluidic sensors based on LTCC technology.