User's Manual

Cinterion
®
ALS1-US Hardware Interface Overview
4 Antenna Interfaces
25

ALS1-US_HIO_v01.000 2013-08-14
Confidential / Preliminary
Page 24 of 34
4 Antenna Interfaces
4.1 GSM/UMTS/LTE Antenna Interface
The ALS1-US GSM/UMTS/LTE antenna interface comprises a GSM/UMTS/LTE antenna as
well as a UMTS/LTE Rx diversity/MIMO antenna to improve signal reliability and quality
1
. The
interface has an impedance of 50
. ALS1-US is capable of sustaining a total mismatch at the
antenna interface without any damage, even when transmitting at maximum RF power.
The external antennas must be matched properly to achieve best performance regarding radi-
ated power, modulation accuracy and harmonic suppression. Matching networks are not in-
cluded on the ALS1-US PCB and should be placed in the host application, if the antenna does
not have an impedance of 50
.
Regarding the return loss ALS1-US provides the following values in the active band:
1.
By delivery default the UMTS/LTE Rx diversity/MIMO antenna is configured as available for the module
since its usage is mandatory for LTE. Please refer to [1] for details on how to configure antenna settings.
Table 9: Return loss in the active band
State of module Return loss of module Recommended return loss of application
Receive > 8dB > 12dB
Transmit not applicable >
12dB
Idle <
5dB not applicable