User's Manual

µLink System Manual 862-01545
Page 8 Issue 1b
Multipath Effects
Refer to Figure 4. The µLink digital radio operates at a
frequency of 2.4 GHz. It is likely that it will be
influenced by the effects of multipath. Understanding
these effects will help to install the µLink digital radio
link and maximise the reliability of the link.
Multipath fade occurs when the receiving antenna
receives not only the direct signal from the transmitting
antenna but also a signal from the transmitting antenna
that has reflected off the ground or nearby obstacles.
The reflected signal takes a longer path to reach the
receiver and acts as an interferer since it is not in phase
with the direct signal. The amplitude of this interferer
can be almost equal to that of the direct path, thus
degrading the link.
Multipath is dependent on transmit frequency and the
specific geometry of the link such as antenna heights,
distance between the antennas and the local terrain. To
counteract multipath, the installer can change the
frequency at which the link operates (a change by 1
channel should be sufficient) or slightly adjust the height
of one or both of the antennas ( a change of 0.5m is
typical, but this depends on the geometry of the link).
User Data
MDR2400 OU
MDR2400 IU
User Data
MDR2400 OU
MDR2400 IU
Direct RF Path
Reflection Path
Figure 4. Multipath Effects.