Microwave and millimeter-wave chip transceivers and radars have become widely available and affordable in the last decade, spurring unprecedented growth in imaging, sensing, and detection applications. These applications define the current and future growth of wireless technology toward integrated communication and sensing services. We will briefly introduce the principles of real-time microwave/millimeter-wave imaging, which allows for “seeing” inside optically opaque objects. Through the concept of the system point-spread function, we will show how to calibrate an imaging system so that…