nRF903 Nordic VLSI, nRF903 Datasheet - Page 24

• Manufacturer Part Number: nRF903
• Description: Multichannel RF Transceiver 433/868/915MHz
• Manufacturer: Nordic VLSI

PRODUCT SPECIFICATION
nRF903 is a true multi-channel transceiver, enabling simultaneous operation of
multiple nRF903 devices in the same environment. This is possible due to high-Q
filtering of the received channel. The IF-filters attenuate the signal power of the
neighbouring channels, thus significantly reducing the risk of jamming and loss of
communication due to nearby traffic. Channel filtering is performed by the external
10.7MHz filter combined with an internal band-pass filter.
The adjacent channel selectivity of a receiver is defined in ETSI EN 300-220-1 as the
ability to demodulate a received signal at the sensitivity limit, with the presence of a
sine component centred in the adjacent channel (see Figure 16). The received power
level of the neighbouring channels, depends on the transmitted power and the distance
to the receiver. Note that the ETSI definition is merely meant as a comparative figure.
The
component, but a modulated spectrum. As the nRF903 is a GFSK-device, the
transmitted adjacent channel power is approx. 25dB
system with the same frequency deviation and datarate, greatly reducing the risk of
destructive interference (Refer to Figure 14 in the
Figure 17 shows typical ACS for the 4 closest channels as a function of input power.
Nordic VLSI ASA
Revision: 3.1
Figure 16. Adjacent channel power attenuation obtained due to IF-filter passband
Figure 17. Adjacent channel selectivity as function of channel spacing and input
ACS is usually lower, as the adjacent channel is not likely to be a sine
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