Sierra Wireless WISMO218 - Manual (Page 80)

WA_DEV_W218_PTS_002 Rev 005 Page 80 of 109
Product Technical Specification &
Customer Design Guidelines
RF Interface
The impedance is 50 nominal and the DC resistance is 0.
RF Connection
The RF input/output of the 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.
Note: 0.5dB can be considered as a maximum value for loss between the WISMO218 and an external
connector.
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
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: