User's Manual

RF Characteristics
A DIVISION OF TRIMBLE
Hardware Overview 37
subsets of that region adopted by countries around the world (917 to 928 MHz). The
following table gives the sensitivity for these factors for a transmit output level of +27
dBm.
The following table shows the impact of “M” value and frequency range on the sensitivity.
T
Receiver Adjacent Channel Rejection
The ThingMagic Nano receives signals that are centered at +250 kHz from its own
carrier. The width of the receive filter is adjusted to match the “M” value of the signal
being sent by the tag. An M value of 2 require the widest filter and an M value of 8
requires the narrowest filter. If operating in an environment where many readers are
present, observe the performance of one reader as the other readers are turned on and
off. If the performance improves when the other readers are turned off, then the system
may be experiencing reader-to-reader interference. This reader-to-reader interference will
be minimized by using the highest “M” value that is consistent with the tag read rates
required by the application.
Region “M” Value Sensitivity
North America and
subsets of 917 to 928
MHz band
8 -57 dBm
4 -57 dBm
2 -49 dBm
EU and India (865 to 868
MHz
8 -61 dBm
4 -61 dBm
2 -53 dBm