Is this true? Is there a formulaic relationship? If gain is a power density, makes sense beam width would be a factor as you'd need to integrate over the solid angle to get m^2. I've never see this correlation before, but would be interesting to understand further.
Is this generally true for all directional transmitters? Even if you have 100% of the beam energy in the main lobe (perfect sidelobe suppression), the 3dB beam width (assuming beam is symmetrical) will contain at most ~50% of the energy? Is there a way to calculate the smallest 3dB beam width...
Agreed, this formula would not make sense for a coherent beam.
Interesting, so Friis breaks down the higher the gain. The 'real' systems I'm thinking about is something like:
http://mainland.cctt.org/istf2008/one.asp
"2.5 GHz band over a 1.6 km distance from an antenna dish to a rectenna. The...
I guess the way I look at this, we can have say 50dBi gain, but a primary beam width that is infinitesimally small (for argument sake). Thus, the total power transmitted by the primary beam can be infinitesimally small since the beam width (for argument sake) is infinitesimally small. Yet, with...
I think what you may be describing is aperture efficiency, which for the sake of the question, is assumed to be lossless. I define beam efficiency as the ratio of power in the main beam over total power radiated...
If we had a transmitter antenna with 40dBi gain, and the same antenna on the receiving end, based on reciprocity, the receiver antenna would be 40dBi too. Assuming a wavelength of 0.1m and transmitted power of 100W over 100m, the received power comes out to be 63W based on this calculator here...
For underground AC transmission, the line charging current prevents the lines from exceeding 100 km due to the close proximity and high capacitance between the line and ground. If the line was made with superconducting material, I think the same distance limitation applies (assuming same power...
I was curious about phased arrays power amplifies and was watching a youtube video on it. They were showing the following slide:
The video mentioned that the Effective Isotropically Radiated Power is the gain per element * power per element * number elements^2
They said if you have an element...
But since the phased array is 'wasting' the energy in areas of destructive interference, seems like the horn or parabolic antennas are better if you don't need active steering. Why are horn antennas better for high frequencies? And which frequencies are considered high?
Sorry for all the...
So a single RF source which generates an RF AC current, then gets amplified through amplifiers, and then that amplified AC current is radiated as RF EM radiation? Is the RF source just an electronic signal generator?
On destructive interference using phased arrays. Why not use horn antenna (or an array of horn anttennas), assuming you just want a forward pointing beam without steering capabilities, or just move the entire horn antenna array to steer?
Even for phased arrays? I thought there were lower power RF sources for each antenna in the array? Like the giant phased arrays you see on battleships.
I think I get it. So you're saying that the loss from the A-B coupler output is wasted energy, and so linking a bunch of routers together and ensuring they all have the same phase, you may be left with a final phased-matched output that has much less power than if you'd just use a single...