Positioning A Module On A Base Board - Espressif Systems ESP32-S3 Hardware Design Manuallines

Chapter 4. PCB Layout Design
• Layer 3 (POWER): GND plane should be applied to better isolate the RF and crystal. Route power traces and
a few signal traces on this layer, provided that there is a complete GND plane under the RF and crystal.
• Layer 4 (BOTTOM): Route a few signal traces here. It is not recommended to place any components on this
layer.
A two-layer PCB design can also be used:
• Layer 1 (TOP): Signal traces and components.
• Layer 2 (BOTTOM): Do not place any components on this layer and keep traces to a minimum. Please make
sure there is a complete GND plane for the chip, RF, and crystal.

4.2 Positioning a Module on a Base Board

If module-on-board design is adopted, attention should be paid while positioning the module on the base board. The
interference of the baseboard on the module's antenna performance should be minimized.
It is suggested to place the module's on-board PCB antenna outside the base board, and the feed point of the
antenna closest to the board. In the following example figures, positions with mark ✓ are strongly recommended,
while positions without a mark are not recommended.
Fig. 2: Placement of ESP32-S3 Modules on Base Board (antenna feed point on the right)
If the PCB antenna cannot be placed outside the board, please ensure a clearance of at least 15 mm around the antenna
area (no copper, routing, or components on it), and place the feed point of the antenna closest to the board. If there
is a base board under the antenna area, it is recommended to cut it off to minimize its impact on the antenna. Figure
Keepout Zone for ESP32-S3 Module's Antenna on the Base Board
antenna feed point is on the right.
When designing an end product, attention should be paid to the interference caused by the housing of the antenna
and it is recommended to carry out RF verification. It is necessary to test the throughput and communication signal
range of the whole product to ensure the product's actual RF performance.
Espressif Systems
shows the suggested clearance for modules whose
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