Specifications

Table Of Contents
Cinterion
®
ELS81-US Hardware Interface Description
2.2 RF Antenna Interface
53
els81-us_hid_v01.004 2017-09-27
Confidential / Preliminary
Page 42 of 107
2.2 RF Antenna Interface
The ELS81-US UMTS/LTE antenna interface comprises a UMTS/LTE main antenna as well as
a UMTS/LTE Rx diversity antenna to improve signal reliability and quality
1
. The RF interface
has an impedance of 50
. ELS81-US is capable of sustaining a total mismatch at the antenna
line without any damage, even when transmitting at maximum RF power.
The external antenna must be matched properly to achieve best performance regarding radi-
ated power, modulation accuracy and harmonic suppression. Antenna matching networks are
not included on the ELS81-US module and should be placed in the host application if the an-
tenna does not have an impedance of 50
.
Regarding the return loss ELS81-US provides the following values in the active band:
2.2.1 Antenna Interface Specifications
For approval reasons it is mandatory to connect/apply the Rx diversity antenna to an existing
antenna. Not connecting/applying the Rx diversity antenna does not necessarily impact the
performance, but may result in approval failures. The minimum antenna efficiency should be
better than 50%.
1. By delivery default the UMTS/LTE Rx diversity 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 7: 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
Table 8: RF Antenna interface UMTS/LTE (at operating temperature range
1
)
Parameter Conditions Min. Typical Max. Unit
LTE connectivity
2
Band 2, 4, 5,12
Receiver Input Sensitivity @
ARP (Dual Antenna; ch.
bandwidth 5MHz)
LTE 700 Band 12 (ch. band-
width 5MHz)
-97 -103.5 dBm
LTE 850 Band 5 (ch. band-
width 10MHz)
-98 -104.5 dBm
LTE AWS Band 4 (ch. band-
width 10MHz)
-100 -103 dBm
LTE 1900 Band 2 (ch. band-
width 10MHz)
-98 -102.5 dBm