Gnss Rf Design Guidelines; Wi-Fi/Bluetooth - Quectel SG560D Series Hardware Design

ANT_GNSS

5.2.3.3. GNSS RF Design Guidelines

Improper design of antenna and layout may cause reduced GNSS receiving sensitivity, longer GNSS
positioning time, or reduced positioning accuracy. To avoid this, follow the reference design rules as
below:
⚫
Maximize the distance between the GNSS RF part and the cellular RF part (including trace routing
and antenna layout) to avoid mutual interference.
⚫
In user systems, GNSS RF signal traces and RF components should be placed far away from
high-speed circuits, switch-mode power supplies, power inductors, the clock circuit of single-chip
microcomputers, etc.
⚫
For harsh electromagnetic environment or a design that requires better ESD protection, diodes with
ultra-low junction capacitance such as 0.5 pF can be selected and added in the antenna interface.
Otherwise, there will be effects on the impedance characteristic of the RF circuit loop or attenuation
of the bypass RF signal may be caused.
Control the impedance of either feeder line or PCB trace to 50 Ω, and keep the trace length as short
⚫
as possible.
⚫
Refer to Chapter 5.5 for the GNSS reference circuit design.
5.3. Wi-Fi/Bluetooth (SG560D-WF)
The module provides one shared antenna interface ANT_WIFI_BT to suppport Wi-Fi and Bluetooth
functions. The interface impedance is 50 Ω. You can connect external antennas such as PCB antenna,
sucker antenna and ceramic antenna to the module via the interface to achieve Wi-Fi and Bluetooth
functions. The module further provides one Wi-Fi antenna interface ANT_WIFI_MIMO to support Wi-Fi
2 × 2 MU-MIMO, tri-band 2.4 GHz, 5 GHz and 6 GHz function. The module complies with IEE
802.11a/b/g/n/ac/ax and supports Dual Band Simultaneous (DBS) with dual MAC.
SG560D_Series_Hardware_Design
Module
Figure 28: Reference Circuit for GNSS Active Antenna
3V3
Active Antenna
R1
C1 C2
10 Ω
1 μF
100 pF
L1
56 nH
C3
R4
0 Ω
100 pF
R3 R5
NM
NM
Smart Module Series
99 / 134