User's Manual

USER MANUA
L
V0.82
© 2010 EnOcean | www.enocean.com TCM 300 / 300C / 320 / 320C User Manual V0.82 | Page 21/43
TCM 300 / 300C / 320 / 320C
3 .2 Ant e nna options TCM 3 0 0 / TCM 3 0 0 C
3 .2 .1 Over view
Several antenna types have been investigated by EnOcean. They all have advantages and
disadvantages as shown in the following table.
Advant a ge s Disadvant a ge s
W hip Ant enna ( 1 5 cm @ 3 1 5 MHz, 8 .6 cm @ 8 6 8 MHz)
Cheap Automatic placement difficult
Omnidirectional Bending influences performance
Large size
Chip An t enna ( AM D 1 1 0 3 - ST0 1 @ 3 1 5 M Hz/ 8 6 8 MHz)
Omnidirectional Expensive
Small size
Very sensitive to environment (GND plane,
components), minimum distance space to
other components needed
Automatic placement possible
Splatch Antenna ( AN T- 3 1 5 - SP1 @ 3 1 5 M Hz, AN T- 8 6 8 - SP1 @ 8 6 8 M H z)
Omnidirectional Expensive
Not very sensitive to environment, low
distance space to other components re-
quired
Large size
Automatic placement possible
Helical Antenna ( AN T- 3 1 5 - H E @ 3 1 5 M Hz)
Omnidirectional
Large distance space to other components
required
Cheap Large size (3D)
Through hole component, no SMT
868 MHz modules used in Europe do not need additional approval if the external antenna
fulfils the following requirements:
Antenna type Passive Mandatory for radio approval
Center Frequency 868.3 MHz Mandatory for radio approval
Impedance ~50 Ohm Mandatory for radio approval
Maximum gain ≤ 8 dBd Mandatory for radio approval
VSWR ≤ 1.5:1 Important for compatibility with EnOcean protocol
Return Loss > 14 dB Important for compatibility with EnOcean protocol
Bandwidth ≤ 20 MHz Important if 10V/m EMC required for device