This is my first ever RF PCB project and it'd be great to receive some guidance to make this project 'first-time-right'.

First PCB

It's purpose is to transmit and receive signals at two different frequencies: 125khz and 315Mhz. To transmit and receive 315Mhz signals I used CC1101 chip modules and for 125Khz I used EM4095 chip IC. I am trying to implement 2-layer PCB due to lower costs compared to 4-layer PCB. I tried keeping top-layer for DC power lines and connections between ICs, while using bottom-layer for GND, although I was forced to route connections between CC1101 modules and ATMEGA via bottom-layer. This is my first PCB project and I'd like to make it 'first-time right', so any suggestions are welcomed! What did I do wrong and what should be improved? Here's project editor page: https://easyeda.com/editor#id=|cae05dd5d4744d7285097ac5ad078f11|a4b1ecae88b340f59224d628c10a1dfd

EDIT: I have encounted GND routing issues with few components on this PCB, which I fixed by adding solid copper plane to the board and those components seemed to connect with GND. Hovewer this didn't resolve grounding issues for CC1101 components, footprints for which I created myself: U10, U9 and U11. Anyone could offer advice with that? Cheers.

  • \$\begingroup\$ It might help others to know what frequency does your circuit operate. For some people RF is above 30GHz and everything else is just some trivial DC thing (no, it is of course not!), while others consider an 1MHz signal RF as well. PCB material might be important as well. I do not see any transmission lines so I guess you are at a very low frequency range. I have not seen any antenna nor a connector on your PCB. Why not 4-layer? Your ground will suffer due to the many components. separate the RF gnd from the rest. \$\endgroup\$ Mar 17, 2019 at 9:35
  • \$\begingroup\$ And C2, series connected to the power supply cannot be right ;) \$\endgroup\$
    – carloc
    Mar 17, 2019 at 10:05
  • \$\begingroup\$ Horror Vacui, CC1101 modules transmit and receive at about 315 Mhz, while EM4095 transmits signal at 125khz. Have you not noticed T2 coil antenna connector attached to EM chip? I was hoping to make a 2-layer PCB due to it's lower cost compared to 4-layers.I left top-layer for DC power lines and other connections between ICs and bottom layer for ground, although for CC1101 chips I was forced to use route their connections to ATMEGA using the bottom layer. \$\endgroup\$
    – beginner
    Mar 17, 2019 at 14:55
  • \$\begingroup\$ carloc, Thank you for pointing that out! I have updated my PCB accordingly, could you take look at it? Are there other improvements I could make? \$\endgroup\$
    – beginner
    Mar 17, 2019 at 15:02
  • \$\begingroup\$ You're shorting your 3.3V rail to the GND pin on U1. \$\endgroup\$
    – Matt Young
    Mar 17, 2019 at 16:27


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