Integration Manual

LISA-U series - System Integration Manual
3G.G2-HW-10002-A3 Preliminary Design-In
Page 120 of 160
2.4 Antenna guidelines
Antenna characteristics are essential for good functionality of the module. Antenna radiating performance has
direct impact on the reliability of connections over the Air Interface. A bad termination of the ANT pin (main RF
input/output) and the ANT_DIV pin (RF input for diversity receiver provided by LISA-U230 modules) can result in
poor performance of the module.
The following parameters should be checked:
Item
Recommendations
Impedance
50 Ω nominal characteristic impedance
Frequency Range
Depends on the LISA-U series module HW version and on the Mobile Network used.
LISA-U100, LISA-U120:
 824..960 MHz (GSM 850, GSM 900, UMTS B5)
 1710..1990 MHz (GSM 1800, GSM 1900, UMTS B2)
LISA-U110, LISA-U130:
 824..960 MHz (GSM 850, GSM 900, UMTS B8)
 1710..2170 MHz (GSM 1800, GSM 1900, UMTS B1)
LISA-U200-00:
 824..960 MHz (GSM 850, GSM 900, UMTS B5, UMTS B6)
 1710..2170 MHz (GSM 1800, GSM 1900, UMTS B1, UMTS B2)
LISA-U200-01, LISA-U230-01:
 824..960 MHz (GSM 850, GSM 900, UMTS B5, UMTS B6, UMTS B8)
 1710..2170 MHz (GSM 1800, GSM 1900, UMTS B1, UMTS B2, UMTS B4)
Input Power
>2 W peak
V.S.W.R
<2:1 recommended, <3:1 acceptable
Return Loss
S
11
<-10 dB recommended, S
11
<-6 dB acceptable
Table 45: General recommendation for GSM antenna
The antenna gain shall remain below the levels reported in the chapter 1.15.3.2 to preserve
the original u-blox FCC ID.
Please note that some 2G and 3G bands are overlapping. This depends on worldwide band allocation for
telephony services, where different bands are deployed for different geographical regions.
If the LISA-U110, LISA-U130 or LISA-U2 series modules are planned for use on the entire supported bands, then
an antenna that supports the 824..960 MHz and the 1710..2170 MHz frequency range should be selected. If the
LISA-U100 or LISA-U120 modules are planned for use with the entire range of supported bands, then an
antenna that supports the 824..960 MHz and the 1710..1990 MHz frequency range should be selected.
Otherwise, for fixed applications in specific geographical region, antenna requirements can be relaxed for non-
deployed frequency bands. Refer to the operating RF frequency bands table in LISA-U1 series Data Sheet [1] and
LISA-U2 series Data Sheet [2] for the detailed uplink and downlink frequency ranges of each supported band.
LISA-U230 modules provide 2G and 3G dynamic receive diversity (Rx diversity) capability to improve the quality
and reliability of the wireless link. This feature can be optionally used connecting a second antenna to the
ANT_DIV pin, to receive an RF input signal that is processed by the module to increase the performance. All the
antenna guidelines and recommendations reported are applicable also to the Rx diversity antenna design, even if
the antenna for the Rx diversity is not used to transmit.
GSM antennas are typically available as:
 Linear monopole: typical for fixed applications. The antenna extends mostly as a linear element with a
dimension comparable to lambda/4 of the lowest frequency of the operating band. Magnetic base may be
available. Cable or direct RF connectors are common options. The integration normally requires the
fulfillment of some minimum guidelines suggested by antenna manufacturer
 Patch-like antenna: better suited for integration in compact designs (e.g. mobile phone). These are mostly
custom designs where the exact definition of the PCB and product mechanical design is fundamental for
tuning of antenna characteristics