I'm learning about an antenna theory and have a few question. According to the attached image. Can anybody explain what's going on in the image? I've done lots of calculation, but still have no idea what's going on. My question is 1. How dipole produce a loop of electric field? (How a loop of electric field are made?) 2. Why does the bigger loop of electric field produce high electric field and lower as the loop become smaller? 3. Why does the smallest loop produce the highest magnetic field? (Isn't loop of higher electric field produce higher magnetic field?) Sorry for my bad English.