Reference Design Of Rf Antenna Interface - Quectel EC21 Series Hardware Design

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B40

5.1.3. Reference Design of RF Antenna Interface

A reference design of ANT_MAIN and ANT_DIV antenna pads is shown as below. It should reserve a
π-type matching circuit for better RF performance. The capacitors are not mounted by default.
NOTES
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.
π-type
3. Place the
possible.
EC21_Hardware_Design
699~716
777~787
815~830
830~845
832~862
814~849
703~748
2300~2400
Module
ANT_MAIN
ANT_DIV
Figure 31: Reference Circuit of RF Antenna Interface
matching components (R1, C1, C2, R2, C3, C4) as close to the antenna as
729~746
746~756
860~875
875~890
791~821
859~894
758~803
2300~2400
Main
antenna
R1 0R
C2
C1
NM
NM
Diversity
antenna
R2 0R
C4
C3
NM
NM
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LTE Module Series
EC21 Hardware Design
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MHz
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