Exposing a Radiation-Hardened 2.4 GHz Wi-Fi Receiver to 500 Kilograys

Exposing the Wi-Fi chip to gamma radiation. (Credit: Yasuto Narukiyo et al, 2026) From outer space to down here on Earth, there are many places where ionizing radiation levels are high enough that they effectively bar access for humans, but also make life miserable for anything containing semiconductor technology. This is especially true for anything involving wireless communications, such as Wi-Fi. However, recently Japanese researchers have created a Wi-Fi chip that is claimed to be so radiation-hardened that it can be used even in gamma ray-rich environments, such as in the worst contaminated depths of the Fukushima Daiichi nuclear reactor. The indicated dose exposure of 500 kilograys that the chip survived during testing is quite significant. A single gray (Gy) is the absorption of one joule of energy per kilogram of matter. In radiation therapy, a solid epithelial tumor can receive as much as 60 to 80 Gy in a single dose, for example. That this Wi-Fi chip was still able to function after such a large cumulative dose was therefore quite impressive, as it rivals what space-based probes receive over numerous years. Unfortunately, the research paper is paywalled, but the PR article from the Tokyo Institute of Science fills in a few more details along with the IEEE Spectrum article. The key was reducing the number of transistors to offer as few targets for radiation as possible. Further inductors were used instead of transistors, for example, variable-gain, as these are less sensitive to ionizing radiation. Remaining transistors were physically enlarged, reducing the number of parallel segments and using NMOS transistors instead of PMOS, due to the latter’s higher radiation resistance. Although degradation in receiver performance was observed after successive blasts at 300 kGy and then 500 kGy, the change was on the order of 1.5-1.6 dB. The next challenge is to make a Wi-Fi transmitter, which is much harder and may require the addition of materials like diamond. Designing for a hostile radiation environment is an art form unto itself . And if you are generating radiation, you have to be extra careful .