does peak dBi mean you actually receive more energy in that direction, or just that you've filtered out energy from everywhere else? (I.e. 20dBi yagi-uda vs 20dBi parabolic)
My initial assumption is that a yagi-uda with 20dBi gain, is simply filtering out the radiation coming from directions other than that with peak gain and doesn't actually "catch" more radiation from that direction than a regular dipole? Meanwhile the reflector design "catches" a large surface area of parallel radiation and condenses it at the feed, meaning it performs BOTH tasks of filtering out non-incident radiation AND collecting more radiation from the direction of highest gain?
But If that were the case, and I must assume I just misunderstand how dBi works, then wouldn't the simulations for a yagi-uda just have 0dBi in the target direction but massively negative dBi in other directions instead of say, +20dBi in one direction, and then falling off to single digit and negative figures off-axis?
If somehow the yagi "magics" extra energy despite not having more aperture, then I guess it's to do with the waves interfering with the parasitics and having more chances to interact with the EM field, and thus more energy is received?
