LTE Module Series
EG95 Hardware Design
EG95_Hardware_Design 52 / 81
1.
Keep a proper distance between the main antenna and the Rx-diversity antenna to improve the
receiving sensitivity.
2.
ANT_DIV
function is enabled by default.
AT+QCFG="diversity",0
command can be used to disable
receive diversity.
3.
Place the
π-type
matching components (R1/C1/C2, R2/C3/C4) as close to the antenna as possible.
5.1.4.
Reference Design of RF Layout
For user’s PCB, the characteristic impedance of all RF traces should be controlled as 50
Ω
. The
impedance of the RF traces is usually determined by the trace width (W), the materials’ dielectric constant,
the distance between signal layer and reference ground (H), and the clearance between RF trace and
ground (S). Microstrip line or coplanar waveguide line is typically used in RF layout for characteristic
impedance control. The following are reference designs of microstrip line or coplanar waveguide line with
different PCB structures.
.
Figure 31: Microstrip Line Design on a 2-layer PCB
Figure 32: Coplanar Waveguide Line Design on a 2-layer PCB
NOTES