EVAL-ADF7021DB2 View Datasheet(PDF) - Analog Devices
Part Name
Description
MFG CO.
'EVAL-ADF7021DB2' PDF : 44 Pages View PDF
Preliminary Technical Data
SPECTRAL SHAPING
Gaussian or raised cosine filtering can be used to improve
transmit spectral efficiency. The ADF7021 supports Gaussian
filtering (BT = 0.5) on 2FSK modulation. Raised cosine filtering
(alpha = 0.5) can be used with 2FSK, 3FSK, or 4FSK
modulation.
Gaussian Frequency Shift Keying (GFSK)
Gaussian frequency shift keying reduces the bandwidth
occupied by the transmitted spectrum by digitally prefiltering
the transmit data. The bandwidth time (BT) product of the
Gaussian filter used is 0.5.
Gaussian filtering can just be used with 2FSK modulation. This
is selected by setting Bits R2_DB[4:6] to 001.
Raised Cosine Filtering
Raised cosine filtering provides digital prefiltering of the
transmit data using a rasied cosine filter with a roll-off factor
(alpha) of 0.5. Rasied cosine filtering can be used with 2FSK,
3FSK, and 4FSK.
Raised cosine filtering is enabled by setting Bits R2_DB[4:6] as
outlined in Table 7.
ADF7021
MODULATION AND FILTERING OPTIONS
The various modulation and data filtering options are described
in Table 7.
Table 7. Modulation and Filtering Options on the ADF7021
Modulation
Data Filtering R2_DB[4:6]
2FSK
None
000
Gaussian
001
Raised cosine
101
3FSK
None
010
Raised cosine
110
4FSK
None
011
Raised cosine
111
Oversampled 2FSK None
100
Rev. PrI | Page 17 of 44
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