EM_550_G2.book Seite 67 Donnerstag, 27. November 2003 1:33 13
Diversity reception
The two receivers of the EM 550 G2 operate on the “true diversity” principle:
A receiving antenna receives not only the electromagnetic waves which reach it by a direct path, but also the reflections of these waves which are created in the room by walls, windows, ceilings and fittings. When these waves are superimposed, destructive interference occurs, which can also be called “field strength gaps”. Repositioning the receiving antenna can bring a solution. With mobile transmitters, however (which all radiomicrophones are), the “field strength gap” will then occur with a different transmitter position. These “field strength gaps” can only be eliminated with true diversity receivers.
In true diversity, instead of one antenna and one receiver there are now two antennas and two receiver sections. The antennas are spatially separated. By means of a comparison circuit, the receiver section with the strongest RF signal is always switched to the common AF output. The risk of the occurrence of “field strength gaps” in both antennas at the same time is virtually nonexistant.
The receiver display panel shows the active diversity section (I or II) .
Control signal |
Receiver section I
Electronic
AF signal
Control signal |
Receiver section II
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