Siemens Desigo TRA Engineering, Mounting And Installation Manual page 75

Penetration angle
Solution
Mounting the antenna
Siemens
Building Technologies
The angle at which a transmitted signal hits the wall plays an important role. The
effective wall strength and thus the dampening of the signal depends on the angle.
The signals should run vertical to the walls as much as possible. Avoid wall
recesses as much as possible.
Eliminate excessively flat penetration angles by repositioning the transmitter and/or
receiver antenna or use a repeater.
Do not mount the receiver antenna or a receiver with internal antenna on the same
wall as the transmitter. RF waves are subject to disruptive refraction or reflection
near walls. It is better to mount the receiver on the next or opposite wall. The
antenna for devices with featuring external antennas should be mounted in a
centralized location in the room. Where possible, the antenna should be at least 10
cm from corners or cement ceilings.
Tip Avoid RF transmission along wall surfaces (e.g. in a long hallway as
well).
The ideal mounting location of the receiver's antenna is a central location in the
room. "Magnetic foot antenna" (e.g. Hirschmann MCA 1890 MH) must attach to a
large a metal surface as possible to provide a sufficient counter polarity. For
example, mounting the antenna on a ventilation duct. Conversely, a "patch
antenna" (surface antenna, e.g. HAMA MiniPlanar 38499) must be mounted in a
non-metal ceiling or drywall, for example, in a cavity wall socket of the right size
(see image below). A patch antenna cannot normally be mounted directly in
cement or in direct proximity to metal. One exception is the "metal patch antenna
MCA 1890MP" by the Hirschmann company. The flat antenna can be attached
discretely and directly to a metal ceiling.
For additional details on selected suitable plugs, please refer to the application
note "AN103 External Antennas" by EnOcean.
Desigo TRA Engineering, mounting and installation
EnOcean RF networks
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CM111043en_09
2016-02-22