User's Manual

13 (23)
2011-06-29
NUR-05W Implementation Guide v0.7
CONFIDENTIAL
5
RF PARAMETERS
5.1 Output power
Maximum output power is +27dBm (500mW). Power can be adjusted by 1dB steps. There is 19 steps
so minimum output value is 8dBm what equals 6mW power. When using high output power it must
be remembered that then antennas VSWR comes even more important. Because high output power
combined with antenna with poor VSWR means that lot of power is reflected back to receiver.
5.2 Receiver sensitivity
Maximum sensitivity of receiver is -86dBm. Receiver can handle +15dBm power coming backwards to
RF_OUT pin.
5.3 Modulation
It is possible to use ASK (amplitude shift keying) or PR-ASK (phase reversed amplitude shift keying)
modulation. Tags that are compliant with ISO18000-6C (EPC C1G2) must support both of these
modulations. PR-ASK has lower transmission data rate and because of that it has narrower output
spectrum. That’s why it is recommended to be used when operating in DRM mode. In other hand
some older tag IC might work better with ASK modulation, because it is easier to tag to demodulate
ASK modulated transmission. By default the modulation is set to PR-ASK.
5.4 Link frequency
Link frequency affects to frequency offset of tags replay in order to readers carrier wave. For example
when used link frequency is 256 kHz, tag will replay at frequency of reader transmission frequency ±
256 kHz. Selectable parameters are 160, 256 and 320 kHz. Tags that are compliant with ISO18000-6C
(EPC C1G2) must support all these parameters. Link frequency also affects tag to reader data rate
which is calculated by formula below:
Tag to reader data rate = (Link frequency / Miller coding)
By default link frequency is set 256 kHz. Default settings must be used when operating in DRM mode.