Ferrite LTCC Based Reconfigurable and Tunable Circuits and Antennas
Low-Temperature Co-fired Ceramic (LTCC) is a mature medium for SoP applications. Efficient passive elements can be designed in LTCC because of its low losses. The introduction of a high-dielectric constant ferrite material in the package not only helps to miniaturize the components but also permits the control of the devices made from it.
Overview
Low-Temperature Co-fired Ceramic (LTCC) is a mature medium for SoP applications. Efficient passive elements can be designed in LTCC because of its low losses. The introduction of a high-dielectric constant ferrite material in the package not only helps to miniaturize the components but also permits the control of the devices made from it. Ferrite allows the properties of the package to be dynamically altered, meaning that the package will have the ability to control the signals that are passing through it. Therefore, ferrite LTCC is a perfect candidate for tunable passive elements. This SoP work is an attempt to push the package beyond merely providing embedded passives, wiring, and physical protection: the package itself becomes the device.
These circuits and antennas are frequency tuned by a variable magnetostatic field produced in a winding that is completely embedded inside the ferrite LTCC substrate. Embedded windings have reduced the typically required magnetic bias field for antenna tuning by over 95%. The fact that large electromagnets are not required for tuning makes ferrite LTCC with embedded bias windings an ideal platform for advanced tunable System-on-Package (SoP) applications. This concept is useful for applications such as DBS-TV (Direct Broadcast Satellite Television) reflectarrays, where reconfigurable coverage is required, or for multi-band wireless sensor systems.
