nRF903 Nordic VLSI, nRF903 Datasheet - Page 22

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

PRODUCT SPECIFICATION
Figure 14 a). Transmitted nRF903 spectrum
Figure 14 b). Comparable FSK spectrum
( f = 23kHz, BR = 76.8kbit/s, BT
= 0.5)
( f = 23kHz, BR = 76.8kbit/s)
GFSK
A cost-saving feature of the nRF903 transceiver is on-chip mirror image cancellation.
All heterodyne receivers have a mirror image frequency for a given channel, which
may cause in-band interference.
The nRF903 mirror image frequency is always positioned 21.4272MHz below the
received channel, regardless of channel number or frequency band. As the nRF903
mirror image is attenuated by use of an on-chip quadrature cancellation technique, a
costly external SAW/crystal-filter may be avoided.
Typical attenuation of the mirror image frequency is 30dB.
Nordic VLSI ASA
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Vestre Rosten 81, N-7075 Tiller, Norway
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Phone [phone]
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Fax [phone]
Revision: 3.1
December 2002
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