Hello, I am very new to this and don't know where to start. I am interested in establishing communication between two devices. The primary goal will be to frequently track the distance between these two objects, and if the distance takes on a certain value, execute some action. There is more to it, but that is the basics of it. Lets say a max distance of 20-30m. The devices are portable. Communication will be in open space (essentially no obstructions). Higher the frequency, the smaller the antenna? Any help is appreciated.