SARA-G450 - System integration manual
UBX-18046432 - R08 Design-in Page 117 of 143
C1-Public
2.13.2 Layout checklist
The following are the most important points for a simple layout check:
Check 50 nominal characteristic impedance of the RF transmission line connected to the ANT
pad (antenna RF input/output interface).
Follow the recommendations of the antenna producer for correct antenna installation and
deployment (PCB layout and matching circuitry).
Ensure no coupling occurs between the RF interface and noisy or sensitive signals (like analog
audio input/output signals, SIM signals, high-speed digital lines).
The VCC line should be wide and short.
Provide the suggested bypass capacitors close to the VCC pins implementing the recommended
layout and placement, especially if the device integrates an internal antenna.
Route the VCC supply line away from sensitive analog signals.
Ensure clean grounding.
Optimize placement for minimum length of RF line and closer path from DC source for VCC.
Route analog audio signals away from noisy sources (like RF interface, VCC, switching supplies).
The audio output lines on the application board must be wide enough to minimize series
resistance.
Keep routing short and minimize parasitic capacitance on the SIM lines to preserve signal
integrity.
Ensure optimal thermal dissipation from the module to the ambient.
2.13.3 Antenna checklist
Antenna termination should provide 50 characteristic impedance with VSWR at least less than
3:1 (recommended 2:1) on operating bands in the deployment geographical area.
Follow the recommendations of the antenna producer for correct antenna installation and
deployment (PCB layout and matching circuitry).
Ensure compliance with any regulatory agency RF radiation requirement.
Follow the guidelines in section 2.4.2 to ensure correct antenna detection functionality, if required.
To Next Page
Loading...
Need help?
General