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Diversity antennas
On Apr 28, 3:42*pm, JIMMIE wrote:
On Apr 28, 3:59*pm, Art Unwin wrote: On Apr 28, 1:53*pm, Michael Coslo wrote: Jeff Liebermann wrote: A link to the Wikipedia page would probably have been sufficient: http://en.wikipedia.org/wiki/Diversity_scheme The problem is that NONE of the diversity schemes mentioned in the Wikipedia article apply to the single antenna example under discussion. *In my never humble opinion, there's no way to provide any form of diversity reception improvement with a single antenna, unless one also has two feeds, going to two different receivers, and ending in either a decision switch, or some form of intelligent combiner. * Trying to wrap my mind around this... I wouldn't know how splitting the signal to two receivers would work. The issue arises at the antenna doesn't it? Indeed, if a single wire antenna would work for diversity reception, wouldn't it then follow that you would not have to use diversity reception? The signal would already be there for you. Seems like a simple test could answer this one. * * * * - 73 de Mike N3LI - I think the first place to start is to what the actual antenna pattern represents in terms of polarity. For instance, we have two vectors outside the earths boundary thus you must have two vectors inside the arbitrary *boundary. Obviously the gravity vector will be at right angles to the earths surface. The other vector representing the rotation of the earth will naturally be an circular pattern which is the "saucer" pattern portion of the overall pattern, which is what hams mainly use. Thus we have to make the first determination as being what each portion of the pattern represents in terms of polarity, the centre being straight plume field and the bottom circular field which is a rotational vector. Since they are in vector form we can see them as a stream of particles where the two vectors will be additive. It is only then that the problem of different or the same phase factors *can be ascertained. Definitions applied can be approach later. Personally, I view the gravity vector as linear with the other providing a wobberly helical vector i.e circular. but varying angles to the earths surface. Other thinkers will surely disagree, if only to fight over near field over far field! I have no doubt that gravity effects radio waves in the same manner that it has been proven to effect light. The effects are going to be such that unless your signal is passing by a black hole of no practical concern. Have a great day Art. Jimmie Totally wrong! The vector inside the boundary opposes gravity! The particle has a straight line trajectory and does not fall back to earth during that trajectory.The rotary vector supplies spin to the other vector force just as the dimples in an golf ball or the rifling of a firearm barrel. These same vectors are represented by time varying electrical current (straight line) as well as displacement current which generates a vortex by its circular motion. When the current flow is completely outside the surface of the radiator skin depth disappears as does resistance. So the radiator has a skin of tightly bonded particles upon which the straight line trajectory is imposed. Remember, earth gravity has zero effect on propagation inside a arbitrary boundary otherwise straight line projection could not exist. |
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