RFM65CW Datasheet, PDF (19/71 Pages) List of Unclassifed Manufacturers – ISM RECEIVER MODULE

ADVANCED COMMUNICATIONS & SENSING
The following figure illustrates the AGC behavior::
RFM65CW
DATASHEET
Towards
-125 dBm
16dB
G1
7dB
11dB
G2
G3
9dB
11dB
Pin [dBm]
G4
G5
G6
Higher Sensitivity
Lower Linearity
Lower Noise Figure
Figure 6. AGC Thresholds Settings
Lower Sensitivity
Higher Linearity
Higher Noise Figure
The following table summarizes the performance (typical figures) of the complete receiver:
Table 9
Receiver Performance Summary
Input Power
Pin
Pin < AgcThresh1
AgcThresh1 < Pin < AgcThresh2
AgcThresh2 < Pin < AgcThresh3
AgcThresh3 < Pin < AgcThresh4
AgcThresh4 < Pin < AgcThresh5
AgcThresh5 < Pin
Gain
Setting
G1
G2
G3
G4
G5
G6
Receiver Performance (typ)
P_-1dB
[dBm]
NF
[dB]
IIP3
[dBm]
IIP2
[dBm]
-37
7
-18
+35
-31
13
-15
+40
-26
18
-8
+48
-14
27
-1
+62
>-6
36
+13
+68
>0
44
+20
+75
3.4.3.1. RssiThreshold Setting
For correct operation of the AGC, RssiThreshold in RegRssiThresh must be set to the sensitivity of the receiver. The
receiver will remain in WAIT mode until RssiThreshold is exceeded.
Note When AFC is enabled and performed automatically at the receiver startup, the channel filter used by the receiver
during the AFC and the AGC is RxBwAfc instead of the standard RxBw setting. This may impact the sensitivity of
the receiver, and the setting of RssiThreshold accordingly
3.4.3.2. AGC Reference
The AGC reference level is automatically computed in the RFM65CW, according to:
AGC Reference [dBm] = -174 + NF + DemodSnr +10.log(2*RxBw) + FadingMargin [dBm]
Tel: [phone] Fax: [phone] E-mail: [e-mail] http:/ / www.hoperf.com
Page 19