I'm designing a 4-layer PCB, containing a GPS module (u-blox NEO M9N) and a Taoglas antenna. The GPS antenna should be on the top layer, and the GPS receiver should be on the bottom layer.

Besides the GPS module, my board will have other components like a microcontroller and a CAN transiever.

My layer configuration:

  • Layer 1 (external): GPS Module;

  • Layer 2 (inner): Ground Plane;

  • Layer 3 (inner): Power signals and trails. Maximum 200mA ;

  • Layer 4 (external): Antenna - Due to the manufacturer's recommendations, this layer will have only the antenna.

Had to use an inner layer for signal because of component configuration.

at the moment:

  • Layer 1 (Copper=0.035mm and Prepreg=0.2mm);

  • Layer 2 (Copper=0.0175mm and Core=1.065mm);

  • Layer 3 (Copper=0.0175mm and Prepreg=0.2mm);

  • Layer 4 (Copper=0.035mm).

My question: since I used layer 3 for signals, shouldn't it be further away from layer 4, which contains the antenna?

Interference is easy to occur with this type of antenna. Any nearby signal can cause interference.

Thank you so much

Sorry for my typo.

Eagle Layer Pairs (DRC)

My plan to preserve impedance is to use a filled via.

I can't decide the thicknesses used for the board layers? Can't determine Copper, Prepreg and Core thicknesses? Widths are designed to maintain correct impedance and resistance (depending on track function). I use them as standard widths in the Eagle software.

  • \$\begingroup\$ Why is layer 3 very slightly thinner than layer 2? I would expect them to have the same copper (note: not cooper) thickness. \$\endgroup\$
    – Hearth
    Jun 7, 2021 at 21:03
  • \$\begingroup\$ @christian, are you doing a 4 layer board? Which manufacturer are you using? Also you don't get to decide what the widths are, the place where you get your PCB manufactured does, so you need to use their widths. Nonstandard widths may be very very costly or impossible to manufacture. In addition to design the RF_IN waveguide/transmission line you will need to have the correct width otherwise you won't get 50Ω, the antenna won't be matched and you will have loss (which means less signal and less satellites that can be seen) \$\endgroup\$
    – Voltage Spike
    Jun 7, 2021 at 21:18


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