User's Manual

HE910 Hardware User Guide
1vv0300925 Rev.9 – 07-02-2012
Reproduction forbidden without Telit Communications S.p.A. written authorization - All Rights Reserved page 38 of 80
6 GSM/WCDMA Antenna
The antenna connection and board layout design are the most important aspect in the
full product design as they strongly affect the product overall performances, hence
read carefully and follow the requirements and the guidelines for a proper design.
6.1 GSM/WCDMA Antenna Requirements
As suggested on the Product Description the antenna and antenna transmission line on
PCB for a Telit HE910 device shall fulfil the following requirements:
ANTENNA REQUIREMENTS
Frequency range
Depending by frequency band(s) provided by the
network operator, the customer shall use the most
suitable antenna for that/those band(s)
Bandwidth
(GSM/EDGE)
70 MHz in GSM850, 80 MHz in GSM900, 170 MHz in
DCS & 140 MHz PCS band
Bandwidth
(WCDMA)
70 MHz in WCDMA Band V
80 MHz in WCDMA Band VIII
460 MHz in WCDMA Band IV (see NOTE1)
140 MHz in WCDMA Band II
250 MHz in WCDMA Band I
Impedance
50 ohm
Input power
> 33dBm(2 W) peak power in GSM
> 24dBm Average power in WCDMA
VSWR absolute max
≤ 5:1 (limit to avoid permanent damage)
VSWR recommended
≤ 2:1 (limit to fulfil all regulatory requirements)
When using the HE910, since there's no antenna connector on the module, the antenna
must be connected to the HE910 antenna pad (K1) by means of a transmission line
implemented on the PCB.
In the case the antenna is not directly connected at the antenna pad of the HE910, then
a PCB line is needed in order to connect with it or with its connector.