Antenna Specifications - Sierra Wireless AirPrime SL808 Series Product Technical Specification & Customer Design Manuallines

Product Technical Specification & Customer Design Guidelines
Table 4-18: Main antenna (ANT_PRI) specification
Parameter
Connection loss
VSWR
Radiated gain
a. Preliminary values
b. When Tx power from modem is
c. When Tx power from modem is
50 Proprietary and Confidential - Specifications subject to change

4.8.4 Antenna specifications

The antenna must meet the requirements specified
The optimum operating frequency depends on the application. A dual-band, tri-
band or quad-band antenna should operate in these frequency bands and have
the described characteristics.
a
Min Typ
- -
- -
Low bands 0
High bands
≤ +33 dBm (2W)
≤ +30 dBm (1W)
Note: Sierra Wireless recommends a maximum VSWR of 1.5:1 for both TX and RX bands.
Even so, all aspects of this specification will be fulfilled even with a maximum VSWR of
2:1.
4.8.4.1 Application notes
The following are suggested guidelines for the two antenna ports:
• The antenna should be isolated as much as possible from analog and digital
circuitry (including interface signals).
• On applications with an embedded antenna, poor shielding could dramatically
affect the receiving sensitivity. Moreover, the power radiated by the antenna
could affect the application (TDMA noise, for instance).
• As a general recommendation, all components or chips operated at high
frequencies (microprocessors, memories, DC/DC converter) or other active
RF parts should not be placed too close to the AirPrime SL808X Embedded
Module. In the event that this happens, the correct power supply layout and
shielding should be designed and validated.
• Components near RF connections or unshielded feed lines must be
prohibited.
• RF lines must be kept as short as possible to minimize loss.
• Primary path common for Tx and Rx should be routed on the host PCB using
a 240 micron wide trace with (to withstand high power up to 2W RF) 50  as
impedance up to the antenna connector or launch point. Note: If the
impedance of the module is mismatched, RF performance is reduced signifi-
cantly.
• Should be protected for ESD using a 8 kV-rated suppressor to avoid damage
during antenna assembly, etc. Capacitance should be < 0.2 pF.
a a
Units
Max
0.5 dB
2.3:1
b
5
dBi
c
3
Table 4-18.
Notes
Maximum loss to antenna
Maximum allowed VSWR of antenna
2400058