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Automotive Module Series
AG35 Hardware Design
AG35_Hardware_Design 83 / 129
1. Keep a proper distance between the main antenna and the Rx-diversity antenna to improve receiving
sensitivity.
2. ANT_DIV function is enabled by default. AT+QCFG="diversity",0 command can be used to disable
receive diversity. Please refer to document [2] for details.
5.1.4. Reference Design of RF Layout
For user’s PCB, the characteristic impedance of all RF traces should be controlled to 50Ω. The
impedance of the RF traces is usually determined by the trace width (W), the materials’ dielectric constant,
height from the reference ground to the signal layer (H), and the clearance between RF traces and
grounds (S). Microstrip or coplanar waveguide is typically used in RF layout to control characteristic
impedance. The following are reference designs of microstrip or coplanar waveguide with different PCB
structures.
Figure 34: Microstrip Design on a 2-layer PCB
Figure 35: Coplanar Waveguide Design on a 2-layer PCB
NOTES