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ALS3-US R4 Hardware Interface Overview
5 Antenna Interfaces
34
ALS3-USR4_HIO_v03.915
2017-03-27
Confidential / Preliminary
Page 28 of 44
5
Antenna Interfaces
5.1
GSM/UMTS/LTE Antenna Interface
The ALS3-US R4 GSM/UMTS/LTE antenna interface comprises a GSM/UMTS/LTE main an-
tenna as well as a UMTS/LTE Rx diversity/MIMO antenna to improve signal reliability and qual-
ity
tenna as well as a UMTS/LTE Rx diversity/MIMO antenna to improve signal reliability and qual-
ity
1
. The interface has an impedance of 50
. ALS3-US R4 is capable of sustaining a total
mismatch at the antenna interface without any damage, even when transmitting at maximum
RF power.
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 ALS3-US R4 PCB and should be placed in the host application, if the antenna
does not have an impedance of 50
ated power, modulation accuracy and harmonic suppression. Matching networks are not in-
cluded on the ALS3-US R4 PCB and should be placed in the host application, if the antenna
does not have an impedance of 50
.
Regarding the return loss ALS3-US R4 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
since its usage is mandatory for LTE. Please refer to
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