Quectel EC21 Series User Manual

LTE Standard Module Series
EC21_Series_Hardware_Design
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4.1.5. Reference Design
A reference design of ANT_MAIN and ANT_DIV antenna pads is shown as below. A π-type matching
circuit should be reserved for better RF performance. The capacitors are not mounted by default.
Figure 33: Reference Circuit of RF Antenna Interface
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="divctl",0 can be used to disable receive
diversity. See document [3] for details.
3. Place the π-type matching components (R1 & C1 & C2, R2 & C3 & C4) as close to the antenna as
possible.
LTE-FDD B7 (10 MHz) -97.0 dBm -96.0 dBm -99.5 dBm -94.3 dBm
LTE-FDD B8 (10 MHz) -98.5 dBm -97.0 dBm -101.0 dBm -93.3 dBm
LTE-FDD B20 (10 MHz) -97.5 dBm -99.0 dBm -100.5 dBm -93.3 dBm
LTE-FDD B28 (10 MHz) -98.0 dBm -98.7 dBm -101.0 dBm -94.8 dBm
NOTE

Quectel EC21 Series Specifications

General

Brand	Quectel
Model	EC21 Series
Category	Control Unit
Language	English