Wi-Fi&Bluetooth Module Series
FC64E_Hardware_Design
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Figure 11: Reference Circuit for RF Antenna Interfaces
3.8.3. Reference Design of RF Routing
For user’s PCB, the characteristic impedance of all RF traces should be controlled to 50 Ω. The
impedance of the RF traces is usually determined by the trace width (W), the materials’ dielectric constant,
the height from the reference ground to the signal layer (H), and the spacing 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 12: Microstrip Design on a 2-layer PCB
Figure 13: Coplanar Waveguide Design on a 2-layer PCB
