
High Integrity FM Transceiver
WP-MKX2010
Page 6 of 7
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RSSI Values
The RSSI output provides a dc voltage that is
proportional to the RF signal strength picked up on the
antenna (pin 2) port of the module.
The table below gives typical values of RSSI for varying
degrees of RF signal strength applied.
RF Input (dBm)
RSSI (V)
-105
0,82
-100
0,88
-90
1,12
-80
1,43
-70
1,75
-60
2,06
-50
2,36
-40
2,57
-30
2,6
-20
2,6
Application Information
Antenna Design
The design and positioning of the antenna is as
crucial as the module performance itself in achieving
a good wireless system range. The following will
assist the designer in maximising system
performance.
The antenna should be kept as far away from
sources of electrical interference as physically
possible. If necessary, additional power line
decoupling capacitors should be placed close to the
module.
The antenna ‘hot end’ should be kept clear of any
objects, especially any metal as this can severely
restrict the efficiency of the antenna to receive power.
Any earth planes restricting the radiation path to the
antenna will also have the same effect.
Best range is achieved with either a straight piece of
wire, rod or PCB track @ wavelength (15.5cm @
433.92MHz). Further range may be achieved if the
wave antenna is placed perpendicular in the middle
of a solid earth plane measuring at least 16cm radius.
In this case, the antenna should be connected to the
module via some 50 ohm characteristic impedance
coax.
RF
Helical Antenna
Whip Antenna
34mm @ 433MHz
17 turns equally spaced
= 5mm (inside)
15.5cm @ 433MHz
Figure 2: Antenna Configurations To Be Used
With The WP-MK-X2010