User Manual

G610 GPRS Module Hardware User Manual Page 43 of 47
The following parameters should be checked:
Item Recommendations
Impedance 50 Ω
Frequency
Range
Depends on the Mobile Network used.
GSM900: 880~960 MHz
GSM1800: 1710~1880 MHz
GSM850: 824~894 MHz
GSM1900: 1850~1990 MHz
Input Power >2 W peak
V.S.W.R <2:1 recommended
<3:1 acceptable
Return Loss S11<-10 dB recommended,
S11<-6 dB acceptable
Gain <3 dBic
Typically GSM antennas are available as:
Linear monopole: typical for fixed application. The antenna extends mostly as a linear element
with a dimension comparable to lambda/4 of the lowest frequency of the operating band. Magnetic
base may be available. Cable or direct RF connectors are common options. The integration
normally requires the fulfillment of some minimum guidelines suggested by antenna manufacturer.
Patch-like antenna: better suited for integration in compact designs (e.g. mobile phone). They
are mostly custom designs where the exact definition of the PCB and product mechanical design is
fundamental for tuning of antenna characteristics.
For integration observe these recommendations:
Ensure 50 Ω antenna termination minimize the V.S.W.R. or return loss, as this will optimize the
electrical performance of the module.
Select antenna with best radiating performance.
If a cable is used to connect the antenna radiating element to application board, select a short
cable with minimum insertion loss. The higher the additional insertion loss due to low quality or long
cable, the lower the connectivity .
Follow the recommendations of the antenna manufacturer for correct installation and
deployment
Do not include antenna within closed metal case.