Wireless Microwave Signal Transmission for Cryogenic Applications

Microwave wireless signal propagation in cryogenic environments has applications in radio astronomy and quantum computing. This paper demonstrates for the first time a cryogenic wireless setup and investigates the antenna-to-antenna signal transmission in Liquid Nitrogen (LN) and inside the dilution refrigerator at room temperature (296 K). The antenna under investigation consists of a wideband antenna operating in from 8–12 GHz. The antenna was modelled and designed in CST MWS and fabricated on the Rogers RT/duroid 5880 substrate. The measured transmission coefficient
$(\mathrm{S}_{21})$
results demonstrate that there was reasonable signal transmission between the antenna pairs when tested in LN (77 K) and inside the dilution refrigerator (tested at 296 K). The results indicate that the proposed Over- The-Air (OTA) system is suitable for cryogenic applications down to 77K.