Rf interface, Rf connection, Rf performances – Sierra Wireless AIRPRIME WISMO218 User Manual
Page 76: Antenna specifications, Table 39
WA_DEV_W218_PTS_002
Rev 006
April 29, 2010
76
Product Technical Specification &
Customer Design Guidelines
Interfaces
3.19. RF Interface
The impedance is 50
nominal and the DC resistance is 0.
3.19.1. RF Connection
The RF input/output of the AirPrime WISMO218 is through one of the castellation pins (Pin 21). A
50
stripline can be used to connect to standard RF connectors such as SMA, UFL, etc. for antenna
connection.
Note:
The antenna cable and connector should be chosen in order to minimize loss in the frequency bands
used for GSM900MHz and 1800MHz.
0.5dB can be considered as a maximum value for loss between the AirPrime WISMO218 and an
external connector.
3.19.2. RF Performances
RF performances are compliant with the ETSI recommendation GSM 05.05.
The main parameters for the Receiver are:
E-GSM900 Reference Sensitivity = -109 dBm (typ.)
DCS1800 Reference Sensitivity = -109 dBm (typ.)
Selectivity @ 200 kHz : > +9 dBc
Selectivity @ 400 kHz : > +41 dBc
Linear dynamic range: 63 dB
Co-channel rejection: >= 9 dBc
The main parameters for the Transmitter are:
Maximum output power (EGSM): 33 dBm +/- 2 dB at ambient temperature
Maximum output power (GSM1800): 30 dBm +/- 2 dB at ambient temperature
Minimum output power (EGSM): 5 dBm +/- 5 dB at ambient temperature
Minimum output power (GSM1800): 0 dBm +/- 5 dB at ambient temperature
3.19.3. Antenna Specifications
The antenna must fulfill the requirements listed in the table below.
The optimum operating frequency depends on the application. A dual Band antenna will work in these
frequency bands and should have the following characteristics:
Table 39: Antenna Specifications
Characteristic
AirPrime WISMO218
E-GSM 900
DCS 1800
TX Frequency
880 to 915 MHz
1710 to 1785 MHz
RX Frequency
925 to 960 MHz
1805 to 1880 MHz