LE940B6 HW User Guide
Rev. 2.02
Page 66 of 111
2020-01-10
7.
Antenna(s)
Antenna connection and board layout design are the most important parts in the full
product design, and they have a strong influence
on the product’s overall performance.
Read carefully and follow the requirements and guidelines for a good and proper design.
GSM/WCDMA/TD-SCDMA/LTE Antenna Requirements
The antenna for the LE940B6 device must meet the following requirements:
Table 21: Primary Antenna Requirements
Gain
Gain < 3 dBi
Impedance
50 Ohm
Input power
> 33 dBm(2 W) peak power in GSM
> 24 dBm average power in WCDMA & LTE
VSWR absolute max
<= 10:1
VSWR
recommended
<= 2:1
The antenna for a specific car model must support a given set of RF bands. This set is
determined by the region variant and the specific set of bands within (either the full band
set offered by Titan or a subset per the customer choice). The antenna must have the
proper bandwidth to support the required set of bands and meet the other performance
figures according to the Table 21, along the full bandwidth. The RF bands supported in
each region variant are detailed in Section
2.5.1, RF Bands per Regional Variant
Since there is no antenna connector on the LE940B6 module, the antenna must be
connected to the LE940B6 antenna pad (AD1) by a transmission line implemented on the
PCB.
If the antenna is not directly connected to the antenna pad of the LE940B6, a PCB line is
required to connect to it or to its connector.
GSM/WCDMA/TD-SCDMA/LTE Antenna
– PCB Line Guidelines
•
Make sure that the transmission line’s characteristic impedance is 50 Ohm.
•
Keep the line on the PCB as short as possible since the antenna line loss should
be less than around 0.3 dB.
•
Line geometry should have uniform characteristics, constant cross sections, and
avoid meanders and abrupt curves.
•
Any suitable geometry/structure can be used for implementing the printed
transmission line affecting the antenna.
•
If a ground plane is required in the line geometry, this plane must be continuous
and sufficiently extended so the geometry can be as similar as possible to the
related canonical model.
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