3D printing is a radical innovative process that’s prompting growth in several technological industries. One particular field whose growth has been influenced by 3D printing is antenna design, a relatively unrecognized but important field that’s played a significant role in developing communication technologies for decades. A team of researchers at Ohio State University’s ElectroScience Laboratory has been utilizing this technology to develop what are being described as “hovering” millimeter-wave antenna arrays. These arrays possess the extra signal strength necessary for meeting heightened demands in high-speed communication and data transfer.
As wireless connectivity becomes more ubiquitous, the electromagnetic frequency spectrum becomes increasingly crowded by allowing this to occur. Since antenna design has slowly begun utilizing millimeter waves (with frequencies of 30-300 GHz), these lower frequencies are under so much strain their days of providing continuous bandwidth might be numbered.
“Nowadays we use cellphones for all sorts of wireless communication for voice and video transmission,” says Nima Ghalichechian, assistant professor in electrical and computer engineering that’s leading the project. “There is a need and a growth every year. Every year we need a lot more [signal strength] to send and receive more data than the previous year.”
Compared to fiber-optic cabling, beaming millimeter waves over air is not only cheaper, but could unlock next-generation broadband infrastructure, namely cellular communication in urban settings. The Ohio State team is developing new millimeter-wave antenna arrays through the hybrid fabrication process. The team’s prime objective is to develop scanning arrays on silicon integrated circuits that exhibit radiation efficiency greater than 85 percent. High-efficiency millimeter-waves with this degree of compactness have yet to be realized.
The process combines 3D printing technology and micro-electrical mechanical systems (MEMs). One of the common limitations antenna designs contain is silicon substrates that these arrays must be mounted on, which are prone to weakening any wireless signals. Since the new arrays are designed to “hover” in the air, this mitigates the need for support and consequent negative effects to the signal.
“Think of it like a diaphragm supported by small posts, but it’s mostly floating. The idea is to physically isolate the antenna from the lossy substrate. Suspend it in air…” says Ghalichechian. “The central objective is to develop scanning arrays on silicon integrated circuits that exhibit radiation efficiency of greater than 85 percent. Such compact high-efficiency millimeter-wave arrays have not been realized to date.”
3D printing will compose the lens components attached to the antennas. The team is conducting trial runs with technology producing particular lensing structures that will sharply focus and enhance signals the antenna array generates. Ghalichechian’s team received a three-year $300,000 National Science Foundation grant award to continue developing their miniaturized “hovering” antennas. Upon completion, the project is expected to have a variety of potential applications in several different sectors. Hopes are high this will further improve short-range and satellite communication links, radars, remote sensing, security, and medical imaging.