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Aladdin Digital Infrared Language Distribution
Installation and User Manual
Televic Conference Systems
2011-09-01
19
1.3.6.
Overlapped Footprints and
Multipath Effects
If footprints of two radiators overlap, the total
coverage area may be larger than the sum of the
two separate footprints. In an area with overlap
effect, the individual radiation signals of two
radiators are added, resulting in an increase of the
radiation intensity, larger than the required
intensity.
However, due to the differences in the delays of the
signals from two or more radiators, the signals may
cancel out each other (multipath effect). In a worst-
case situation, loss of reception at some positions
(black spots) may be the consequence.
Figure 1.14 and Figure 1.15 illustrate the effect of
overlapped footprints and differences in signal
delays.
Figure 1.14: Increased coverage area caused by added
radiation power
Figure 1.15: Reduced coverage area caused by
differences in cable signal delay
The lower the carrier frequency, the less susceptible
the receiver is for differences in signal delays.
The signal delays can be compensated by adjusting
the delay compensation switches on the radiators
(see section 3.6).