Fully Additively Manufactured Tunable Active Frequency Selective Surfaces with Integrated On-package Solar Cells for Smart Packaging Applications

A first-of-its-kind fully inkjet-printed electronically tunable active flexible frequency selective surface (FSS) using varactors with integrated on-package solar cells is presented in this paper. Each varactor is biased by a dedicated on-package inkjet-printed solar cell using a low-temperature fabrication process. The solar cell changes its output voltage with variation in light intensities that eventually leads to a change in capacitance of the varactor and overall frequency response of the FSS. The proposed design eliminates the use of labor intensive biasing network, bulky power supply and micro-controllers to tune the FSS frequency response. These structures presents an autonomous, ultra low cost on-package RF shielding mechanism for next-generation of system-on-chip packaging applications that can be tuned on-demand at different frequency bands by simple variation of incident light intensities. Thus making them useful for a wide range of terrestrial, outer-space and EMI shielding applications.