User's Manual

USER MANUAL
TCM 300 / TCM 300C / TCM 300U
TCM 320 / TCM 320C / TCM 320U
4.2 Antenna options TCM 300x
4.2.1 Overview
Several antenna types have been investigated by EnOcean. Please refer to our application
notes AN102, and AN105 which give an overview on our recommendations.
All TCM3x0 modules have been approved with whip antenna, and TCM300U with helical
antenna in addition.
868.300 MHz modules used in Europe do not need additional approval if the external an-
tenna fulfils the following requirements:
Frequency
band
868.300 MHz
ISM
Antenna must be suited for this band
Antenna type
Passive
Mandatory for radio approval
Impedance
~50 Ohm
Mandatory for radio approval
Maximum gain
≤ 0 dBd
Mandatory for radio approval
In addition it is important to fulfill the following requirements in order to achieve compati-
bility with other EnOcean products and to ensure excellent EMI robustness:
VSWR
3:1
Important for compatibility with EnOcean protocol
Return Loss
> 6 dB
Important for compatibility with EnOcean protocol
Bandwidth
20 MHz
Important if 10 V/m EMI robustness required for device
For 315 MHz / 902.875 MHz modules (TCM 300C / TCM 300U) please note
that a full approval is needed if modules are used with antennas other than
the specified antennas.
4.2.2 Whip antenna
315 MHz
Antenna: 150 mm wire, connect to RF_WHIP
Minimum GND plane: 50 mm x 50 mm
Minimum distance space: 10 mm
868.3 MHz
Antenna: 86 mm wire, connect to RF_WHIP
Minimum GND plane: 38 mm x 18 mm
Minimum distance space: 10 mm
902.875 MHz
Antenna: 64 mm wire, connect to RF_WHIP
Minimum GND plane: 50 mm x 50 mm
Minimum distance space: 10 mm