Extremely high frequency (EHF) refers to a range of radio frequencies from 30 gigahertz (GHz) to 300 GHz. This part of the electromagnetic spectrum is used for various applications, including satellite communications, radar systems, and some types of wireless networks. EHF signals can carry large amounts of data but have limited range and are easily absorbed by obstacles like buildings and trees. Due to their high frequency, EHF waves can provide high-resolution imaging and precise targeting in military applications. They are also utilized in scientific research, such as studying atmospheric phenomena. Overall, EHF plays a crucial role in modern communication and technology.