Antennas - insys icom MRX Installation And User Manual

Technical Information

7.3.3 Antennas

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As per EN 2014/53/EU, the operator of a radio equipment must
comply with the harmonisation legislation. This includes in particular
the selection and utilisation of suitable antenna systems. It must be
ensured in particular that devices with radio technology are not
operated without a suitable antenna system for an extended period.
In order to meet the respective cellular radio specification (and improve reception
quality and data rate in downlink), it is necessary to use a second antenna for the
operating modes Rx Diversity (UMTS) or MIMO (LTE) or a MIMO/diversity antenna
with two integrated antennas. The following must be observed when using two in-
dividual antennas.
7.3.3.1 Main antenna
Since the main antenna is both, first reception antenna and only sending antenna,
it should be set-up vertically polarised and omnidirectional to be perfectly aligned
with the base station (that is always vertically polarised). It should be possible to
compensate the attenuation losses of the antenna lead with an appropriate gain of
the antenna.
7.3.3.2 Auxiliary antenna for MIMO / Rx Diversity
When using an auxiliary antenna, it is recommended to use the same type and the
same antenna lead as for the main antenna. It would be adverse if the difference in
gain of the two antennas is too high. The auxiliary antenna is to be installed at an
angle of 90° to receive the horizontally polarised portion of the radio waves that are
least detected
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with adverse transmission. Moreover, the possible data rate increases, in particular
of the base station broadcasts using two antennas.
7.3.3.3 Antenna arrangement
The distance between the antennas should be as close as possible but not fall be-
low ¼ of the maximum wave length (lowest frequency band). Approx. 9 cm would
be ideal in case of 800 MHz (LTE, band 20) for example.
Tests have shown that the right arrangement of the antennas is very important. If
both antennas are set-up vertically for example, the data rate can be worse than for
only one antenna.
7.3.3.4 Outside mounted antenna
When using the outside mounted antennas offered by INSYS, the delivered mount-
ing bracket provides sufficient distance to the wall. If the main antenna is aligned
vertically and the auxiliary antenna is mounted at the same point perpendicular, the
mounting brackets provide also a minimum distance of the antennas at the feeding
point of 10 cm.
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by the main antenna. This allows to compensate negative effects
MRX