Product Info

NB-IoT Module Series
BC660K-GL Hardware Design
BC660K-GL_Hardware_Design
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
Use an impedance simulation tool to accurately control the characteristic impedance of RF traces to
50 Ω.

The GND pins adjacent to RF pins should not be designed as thermal relief pads, and should be fully
connected to ground.

The distance between the RF pins and the RF connector should be as short as possible, and all the
right-angle traces should be changed to curved ones.

There should be clearance under the signal pin of the antenna connector or solder joint.

The reference ground of RF traces should be complete. Meanwhile, adding some ground vias around
RF traces and the reference ground could help to improve RF performance. The distance between
the ground vias and RF traces should be no less than two times as wide as RF signal traces (2 × W).
For more details, see document [4].
4.5. Antenna Requirements
To minimize the loss on RF trace and RF cable, pay attention to the antenna design. The following tables
show the requirements on NB-IoT antenna.
Table 16: Antenna Cable Insertion Loss Requirements
Table 17: Required Antenna Parameters
Band
Requirements
LTE B5/B8/B12/B13/B14/B17/B18/B19/B20/B28/B85
Cable insertion loss: < 1 dB
LTE B1/B2/B3/B4/B25/B66/B70
Cable insertion loss: < 1.5 dB
Parameters
Requirements
Frequency Range
698–2200 MHz
VSWR
≤ 2
Efficiency
> 30 %
Max Input Power (W)
50
Input Impedance (Ω)
50