Ascotel IntelliGate 2025/2045/2065
622 Planning DECT systems Part 3
Fig. 3.22: Example 2: Corner reflector antenna
The same principle applies to all antenna types: The narrower the horizontal and
vertical radiation range, the greater the distances that can be covered. In this con-
nection we talk of antenna gain, which indicates the ratio of the energy radiated
in a particular angle to the radiated energy of a standard antenna (usually a λ/2
dipole antenna). An extreme example of this is the radio relay antenna, which is
used for transmitting radio signals in a targeted direction from one point to the
next.
Fading effect
If an SB-8ANT radio unit is operated with external antennas, an antenna must
always be connected to each of the two antenna connections. The antennas
should have the same radio characteristic and also cover the same range. This
reduces the occurrence of fading effects (caused by radio signals cancelling one
another out through reflections), and considerably improves the connection qual-
ity. If such an effect occurs on one of the antennas, the radio unit automatically
switches over to the second antenna, thereby preventing minor drop-outs. This is
referred to as antenna diversity. Fading effects occur mainly inside and between
buildings, which provide a great deal of reflection surface. Dual antennas inside a
single housing, designed specifically with this effect in mind, are widely available
in the market. That is why the radio units themselves are always equipped with
two internal antennas.
Horizontal
Radiation pattern in relative field strength
Vertical
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