NB-IoT Module Series
BC66 Hardware Design
BC66_Hardware_Design 36 / 57
A reference design of the RF interface is shown as below.
Module
RF_ANT
R1 0R
C1
NM
C2
NM
GND
GND
Figure 23: Reference Design of NB-IoT Antenna Interface
4.4. 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 height 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 24: Microstrip Line Design on a 2-layer PCB
