Evaluation Kit for CMX990
EV9900A
Adjacent Channel Power (ACP)
60dB adjacent channel power can be demonstrated for 12.5kHz channels with G(M)FSK, Bt =
0.27 and 8kbit/s. To achieve this an external LO is required and a TxIF of 45MHz selected.
70dB adjacent channel power can be demonstrated for 25kHz channels with GMSK, Bt = 0.5 and
9.6kbit/s.
Compliance with FCC 47CFR90.210 emission mask D can also be demonstrated using the on-
board Main VCO module, as shown in the following plot. A 45MHz TXIF was used. This is a
12.5kHz channel mask and requires a change in baud rate to 8kbit/s (register $29, 46h) and BT to
0.3.
Marker 1 [T1]
21.30 dBm
420.10000000 MHz
RBW
VBW
SWT
100 Hz
1 kHz
25 s
RF Att
Mixer
Unit
10 dB
-20 dBm
dB
Ref Lvl
30.3 dBm
0
-10
-20
-30
-40
-50
-60
-70
-80
-90
-100
30.5 dB Offset
1 [T1]
21.30 dBm
A
1
420.10000000 MHz
LN
1MAX
1SA
FCC210D
Center 420.1 MHz
5 kHz/
Span 50 kHz
Date:
25.OCT.2007 15:45:05
Figure 5 – FCC 47CFR90.210 emission mask D
Spurious Emissions
EV9900A is not designed to be compliant with spurious emissions limits as transmitter filtering is
not included.
Maximum Usable Sensitivity
Typically –117dBm for 1% BER (9.6kbit/s, Bt = 0.5).
Co-channel Rejection
With an interferer on the same frequency this is typically 7dB for 25kHz channel spacing
operation (9.6kbit/s).
© 2007 CML Microsystems Plc
20
UM9900A/3
CMLMICRO [ CML MICROCIRCUITS ]
