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FIBOCOM L610-LA Series Hardware Guide
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Figure 4-1 RF Reference Circuit Design
Make sure the characteristic impedance of the transmission cable is 50 ohms.
Since the antenna cable loss is less than 0.3dB, keep the PCB routing as short as possible.
PCB LAYOUT should be as straight as possible to avoid vias and layers, and avoid right-angle and
acute-angle routing.
PCB routing should have a good reference ground to avoid other signal line from approaching the
antenna.
A complete ground level is recommended as a reference ground.
Strengthen the connection between the ground around the antenna and the main ground.
Note:
Refer to
FIBOCOM Design Guide_RF Antenna
for specific design details.
4.5 Antenna Design
1) Antenna Efficiency
Antenna efficiency is the ratio of antenna input power to radiated power. Due to the antenna’s return loss,
material loss, and coupling loss, the radiated power is always lower than the input power. Antenna
efficiency > 40% (-4dB) is recommended.
2) S11 or VSWR
S11 indicates the matching degree of the antenna’s 50-ohm impedance, which affects the antenna
efficiency to a certain extent. This indicator can be measured using VSWR test. S11 < -10dB is
