Hey all! Now I'm working on wireless communication, not a physician. In many courses in ECE, we learn about principle of superposition of radio waves. But I have a stupid question which has been considered no wonder so far. There are two radio senders(S1,S2) and one receiver(R). Let's suppoe that the distance between senders and receiver, the waveform frequency, phase and types are exactly same. By principle of superposition, at the position (R), the intensity is getting 4 times than there is only one sender because amplitude of two signals is getting double. What does that mean? It seriously makes me confusing. Does it mean that I can get double power if I use two different sources? There must not be free energy!! So I think that there might be something to lose for this free food. What is the cost I have to pay to get double intensity at the receiver in wireless communication? Thanks in advance!!