LISA-U2 series - System Integration Manual
UBX-13001118 - R19
Early Production Information
Design-In
Page 135 of 175
For example:
Consider a GSM antenna with built-in DC load resistor of 15 k
. Using the +UANTR AT command, the module
reports the resistance value evaluated from
ANT
connector to GND:
Reported values close to the used diagnostic resistor nominal value (i.e. values from 13 k
Ω
to 17 k
Ω
if a
15 k
Ω
diagnostic resistor is used) indicate that the antenna is properly connected
Values close to the measurement range maximum limit (approximately 50 k
Ω
) or an open-circuit
“over range” report (see
u-blox AT Commands Manual
[2]) means that that the antenna is not connected or
the RF cable is broken
Reported values below the measurement range minimum limit (1 k
Ω
) will highlight a short to GND at
antenna or along the RF cable
Measurement inside the valid measurement range and outside the expected range may indicate an improper
connection, damaged antenna or wrong value of antenna load resistor for diagnostic
Reported value could differ from the real resistance value of the diagnostic resistor mounted inside the
antenna assembly due to antenna cable length, antenna cable capacity and the used measurement method
2.5
ESD guidelines
2.5.1
ESD immunity test overview
The immunity of devices integrating LISA-U2 modules to Electro-Static Discharge (ESD) is part of the
Electro-Magnetic Compatibility (EMC) conformity which is required for products bearing the CE marking,
compliant with the R&TTE Directive (99/5/EC), the EMC Directive (89/336/EEC) and the Low Voltage Directive
(73/23/EEC) issued by the Commission of the European Community.
Compliance with these directives implies conformity to the following European Norms for device ESD immunity:
ESD testing standard
CENELEC EN 61000-4-2
[11] and the radio equipment standards
ETSI EN 301 489-1
ETSI EN 301 489-7
ETSI EN 301 489-24
[14], which requirements are summarized in Table 51.
The ESD immunity test is performed at the enclosure port, defined by
ETSI EN 301 489-1
[12] as the physical
boundary through which the electromagnetic field radiates. If the device implements an integral antenna, the
enclosure port is defined as all insulating and conductive surfaces housing the device. If the device implements a
removable antenna, the antenna port can be separated from the enclosure port. The antenna port includes the
antenna element and its interconnecting cable surfaces.
The applicability of the ESD immunity test to the whole device depends on the device classification as defined by
ETSI EN 301 489-1
[12]. Applicability of the ESD immunity test to the specific device ports or the specific
interconnecting cables to auxiliary equipments, depends on device accessible interfaces and manufacturer
requirements, as defined by
ETSI EN 301 489-1
Contact discharges are performed at conductive surfaces, while air discharges are performed at insulating
surfaces. Indirect contact discharges are performed on the measurement setup horizontal and vertical coupling
planes as defined in
CENELEC EN 61000-4-2
For the definition of integral antenna, removable antenna, antenna port, device classification see the
ETSI
EN 301 489-1
The contact and air discharges are defined in
CENELEC EN 61000-4-2
Application
Category
Immunity Level
All exposed surfaces of the radio equipment and ancillary equipment in a
representative configuration
Contact Discharge
4 kV
Air Discharge
8 kV
Table 51: Electro-Magnetic Compatibility ESD immunity requirements as defined by CENELEC EN 61000-4-2, ETSI EN 301 489-1,
ETSI EN 301 489-7, ETSI EN 301 489-24
