LE910C1
Hardware User Guide
1VV0301298 Rev. 1.08 - 2017-11-14
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7.5.
GNSS Antenna Requirements
LE910C1 supports an active antenna.
It is recommended to use antennas as follow:
•
An external active antenna (17dB typ. Gain, GPS only)
•
An external active antenna plus GNSS pre-filter (17dB typ. Gain)
NOTE:
The external GNSS pre-filter is required for the GLONASS application.
The GNSS pre-filter must meet the following requirements:
Source and load impedance = 50 Ohm
•
Insertion loss (1575.42–1576.42 MHz) = 1.4 dB (Max)
•
Insertion loss (1565.42–1585.42 MHz) = 2.0 dB (Max)
•
Insertion loss (1597.5515–1605.886 MHz) = 2.0 dB (Max)
NOTE:
It is recommended to add a DC block to the customer’s GPS application to prevent damage to the
LE910C1 module due to unwanted DC voltage.
NOTE:
It is recommended to add PI matching network near the GPS connector on the application board
in case that RF matching is needed.
7.5.1.
Combined GNSS Antenna
The use of a combined RF/GNSS antenna is NOT recommended. This solution can generate an
extremely poor GNSS reception. In addition, the combination of antennas requires an additional
diplexer, which adds significant power loss in the RF path.
7.5.2.
Linear and Patch GNSS Antenna
Using this type of antenna introduces at least 3 dB of loss compared to a circularly polarized (CP)
antenna. Having a spherical gain response instead of a hemispherical gain response can aggravate
the multipath behavior and create poor position accuracy.
7.5.3.
Front End Design Considerations
Since there is no antenna connector on the LE910C1 module, the antenna must be connected to
the LE910C1 through the PCB to the antenna pad.
If the antenna is not directly connected at the antenna pad of the LE910C1, a PCB line is required.
