ATA5811_06 ATMEL [ATMEL Corporation], ATA5811_06 Datasheet - Page 14

• Manufacturer Part Number: ATA5811_06
• Description: UHF ASK/FSK TRANSCEIVER
• Manufacturer: ATMEL [ATMEL Corporation]

14
ATA5811/ATA5812
Figure 5-5
selectivity and image rejection. This measurement was done 6 dB above the sensitivity level
with a useful signal of 433.92 MHz/FSK/20 Kbit/s/±16 kHz/ Manchester with a level of
–106 dBm + 6 dB = –100 dBm. The figure shows to which extent a continuous wave signal can
surpass –100 dBm until the BER is higher than 10
be 59 dB higher than –100 dBm which is –100 dBm + 59 dB = –41 dBm.
Table 5-6
quencies. Note that sometimes the blocking is measured relative to the sensitivity level (dBS)
instead of the carrier (dBC).
Table 5-6.
The ATA5811/ATA5812 can also receive FSK and ASK modulated signals if they are much
higher than the I1dBCP. It can typically receive useful signals at 10 dBm. This is often referred to
as the nonlinear dynamic range which is the maximum to minimum receiving signal which is
116 dB for 20 Kbit/s Manchester. This value is useful if two transceivers have to communicate
and are very close to each other.
Figure 5-5.
Frequency Offset
shows the blocking performance measured relative to –100 dBm for some other fre-
+0.75 MHz
–0.75 MHz
shows the blocking measurement close to the received frequency to illustrate the
+1.5 MHz
–1.5 MHz
+10 MHz
–10 MHz
Blocking 6 dB Above Sensitivity Level with BER < 10
Close In 6 dB Blocking Characteristic and Image Response at 433.92 MHz
-10.0
60.0
40.0
30.0
20.0
70.0
50.0
10.0
0.0
-1.0
Distance of Interfering to Receiving Signal [MHz]
-0.8
-0.6
-0.4
Blocker Level
–45 dBm
–45 dBm
–38 dBm
–38 dBm
–30 dBm
–30 dBm
-0.2
-3
0.0
. For example, at 1 MHz the blocker can than
0.2
0.4
0.6
-3
0.8
55 dBC/61 dBS
55 dBC/61 dBS
62 dBC/68 dBS
62 dBC/68 dBS
70 dBC/76 dBS
70 dBC/76 dBS
1.0
Blocking
4689F–RKE–08/06