The electronics industry has undergone many changes over the past few years. Nowadays, millimeter wave radar and millimeter wave communication frequently appear in our sight. In particular, Huawei has made remarkable achievements in 5G, and millimeter wave technology has been put on the table. Why does millimeter wave technology play such a key role in 5G and smart cars? Next, let’s take a closer look at the past and present of millimeter wave technology and its continuation.