User's Manual

DE910 Series Hardware User Guide
1vv0301183 Rev.1 – 2015-2-13
Reproduction forbidden without written authorization from Telit Communications S.p.A. - All Rights
Reserved. Page 34 of 70
6. Antenna
The antenna connection and board layout design are the most important parts in the full
product design and they strongly reflect on the product’s overall performance. Read carefully
and follow the requirements and the guidelines for a proper design.
6.1. CDMA Antenna Requirements
The antenna for a Telit DE921 device must fulfill the following requirements:
CDMA Antenna Requirements
Frequency range
Depending
on
the
frequency band(s) provided by the
network operator, the customer must use the most suitable
antenna for that/those band(s)
Bandwidth
70 MHz
in CDMA BC0
53 MHz in CDMA BC10
140 MHz in CDMA BC1
Gain
Gain <
5.12
dBi
in
CDMA BC0
Gain < 5.12 dBi in CDMA BC10
Gain < 6.12 dBi in CDMA BC1
Impedance
50 Ohm
Input power
> 24dBm Average Power in CDMA
VSWR absolute max
≤ 5:1 (Limit to avoid permanent damage)
VSWR recommended
≤ 2:1 (Limit to fulfill all regulatory requirement)
When using the Telit DE921, since there’s no antenna connector on the module, the antenna
must be connected to the DE921 antenna pad (V1) by means of a transmission line
implemented in the PCB.
In the case that the antenna is not directly connected at the antenna pad of the DE921, then a
PCB line is required.