UMTS/HSPA+ Module Series
UC200A-GL_Hardware_Design 52 / 79
ANT_MAIN
R1 0 R
C1
Module
Main
antenna
NM
C2
NM
Figure 28:
Reference Circuit for RF Antenna Interfaces
5.2. Reference Design of RF Routing
For user’s PCB, the ch
aracteristic impedance of all RF traces should be controlled to 50
Ω. The
impedance of the RF traces is usually det
ermined by the trace width (W), the materials’ d
ielectric 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 29: Microstrip Design on a 2-layer PCB