Passive Antenna Reference Design - Quectel L76 Hardware Design

ANTON is an optional pin which can be used to control the power supply of the active antenna. When the
ANTON pin is pulled down, MOSFET Q1 and Q2 are in high impedance state and the power supply for
antenna is cut off. When ANTON pin is pulled high, it will make Q1 and Q2 in the on-state, and VDD_RF
will provide power supply for the active antenna. The high and low level of ANTON pin is determined by
the modules' state.
For minimizing the current consumption, the value of resistor R2 should not be too small, and the
recommended value is 10 kΩ.

5.2.4. Passive Antenna Reference Design

5.2.4.1. Passive Antenna Reference Design without Additional LNA
The following figure is a typical reference design of a passive antenna.
Passive Antenna
Figure 21: Passive Antenna Reference Design without Additional LNA
The components C1, R1 and C2 are reserved for matching antenna impedance. By default, R1 is 0 Ω,
while C1 and C2 are not mounted. D1 is an electrostatic discharge (ESD) protection device to protect one
signal line from the damage caused by ESD. The impedance of RF trace should be controlled to 50 Ω and
the trace length should be kept as short as possible.
5.2.4.2. Passive Antenna Reference Design with Additional LNA
In order to improve the receiver sensitivity and reduce the TTFF, an additional LNA between the passive
antenna and the module is recommended. The reference design is shown as below.
L76&L76-L_Hardware_Design
π
Matching Circuit
R1
0R
GNSS Module Series
Module
RF_IN
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