Telit Wireless Solutions SE868SY-D, Руководство по конструкции аппаратуры, Страница: 26 / 44

SE868SY-D Hardware Design Guide
1VV0301705 Rev. 5 Page 26 of 44 2021-12-15
Not Subject to NDA
• Surround (on both the sides, above and below) the antenna line on PCB with
Ground, avoid having other signal tracks directly facing the antenna line of track.
• The ground around the antenna line on PCB must be strictly connected to the
Ground Plane using vias at least once every 2mm.
• Place EM noisy devices as far as possible from antenna line.
• Keep the antenna line far away from power supply lines.
•
Keep the antenna line far away from GSM RF lines.
•
If there are EM noisy devices around the PCB hosting the module, such as fast
switching ICs, take care of the shielding of the antenna line by burying it inside the
layers of PCB and surrounding it with Ground planes, or shielding it with a metal
frame cover.
• If there are not EM noisy devices around the PCB hosting the module, use a strip-
line on the superficial copper layer for the antenna line. The line attenuation will
be lower than a buried one.
GNSS Antenna Requirements
7.3.1. GNSS Antenna Specification
Item Value
Frequency range
L1: 1559.0 ~ 1610.0 MHz
L5: 1151.0 ~ 1214.0 MHz
Gain
0
~ 30 dB (0 ~ 8 dB for better EMI performance)
Impedance 50
Ω
Noise Figure of LNA < 1.5 (recommended)
VSWR
≤
3:1 (recommended)
Table 22: GNSS Antenna Specification
7.3.2. GNSS Antenna – Installation Guidelines
•
The antenna must be installed according to the antenna manufacturer’s
instructions to obtain the maximum performance from the GNSS receiver.
•
The antenna location must be carefully evaluated if operating in conjunction with
any other antenna or transmitter.