I know the basics about em radiation. However, I’m not in college, and I’m not a genius. I’m really looking for someone that’s willing to help explain this to me in a relatively simple way, without long equations and over complicated phrasing.
I thought that antennas had to be part of a closed circuit, like alternating current circuits...sure maybe there’s a capacitor in there, but it essentially is closed(for ac, not dc necessarily). I’ve seen laptop antennas that appear to have a signal wire and ground wire. The ground wire covers most of the signal wire. Only the ‘antenna’ length is exposed..not covered by ground. It appeared to be a closed circuit(kind of like a loop)..
Well, an rc car/copter antenna appears to be a single rod. I don’t see a ground at the tip or anything. It appears that it’s open circuited. The only thing I’ve gathered from googling for hours is that the em waves(lots of photons) hit the antenna and cause electrons to gather at one end, then the other end of the antenna. This causes a potential difference . I’ve read this only works at high frequencies, although A.M radio also uses a single rod antenna, and it’s only in the kz or mz. I’m just so lost. I’m not trying to claim I know everything I said for a fact. This is just how I interpreted it.
Also, why does the length of an antenna matter so much? I get that if the em wavelength is short, using a smaller antenna is best because it doesn’t receive longer wavelength waves as well. I think that the resonance frequency of the antenna has something to do with this(I’m still a bit confused about how resonance works with an antenna..basically what decides the resonance frequency?). But if photons are striking individual electrons(at least that’s what I’ve learned, although I’ve heard that as a wave, a single photon can strike multiple electrons at once, pushing, then repelling them, which I also don’t understand) But how does the resonant frequency of the antenna have anything to do with the frequency of photons? Why does the resonance frequency correspond directly with the length of the antenna relative to the wavelength of the em wave? Is there something I’m missing here? -Does the length of the antenna have anything to do with the probability of absorbing photons at that same wavelength, without having as high of a probability of absorbing longer photons? But then it would absorb shorter wavelength photons easier based on that logic..
Guys, I’d like to say I’m sorry for the way I word things. I’m not smart. I have a really hard time expressing my questions using conventional terms. I haven’t gone to college or anything, so I don’t know a whole lot. If anyone is willing to try to help me out, I’d really appreciate it. Please feel free to ask me to clarify any of my questions in a way that you’d understand better.