Dear all,

I have completed the designing of a 4-layer RF PCB and the manufacturer ask if it possible to balance the copper at the inner and outer layers.
The stack up is RF SIGNALS-GND-VCC-SIGNALS

This is my first PCB and I don't how to manipulate with copper balancing. Furthermore, I am not sure whether or not this extra copper is going to affect/degrade the performance of my RF PCB. Also, the extra copper shall be grounded or not?

Please find attached some screen shots (in single layer mode) of the layers.

Also, as you can notice I didn't apply vcc plane. Should I apply?

Thanks in advance

 

Dear all,

I have completed the designing of a 4-layer RF PCB and the manufacturer ask if it possible to balance the copper at the inner and outer layers.
The stack up is RF SIGNALS-GND-VCC-SIGNALS

This is my first PCB and I don't how to manipulate with copper balancing. Furthermore, I am not sure whether or not this extra copper is going to affect/degrade the performance of my RF PCB. Also, the extra copper shall be grounded or not?

Please find attached some screen shots (in single layer mode) of the layers.

Also, as you can notice I didn't apply vcc plane. Should I apply?

Thanks in advance

I would suggest to flood both the top and bottom layers with GND plane. keep good clearance to the RF tracks (usually 3-5 times dielectric height).
This will help both copper balance and reduce the radiation/pickup. Also it provide a solid GND connection when you are doing some measurement/modification.

 

First off, what is the frequency and function of the circuit? Are the traces microstrip? If so, have you ever heard of Coplanar Waveguide? Your traces look awful thin. How large is the board? When I design RF circuits, I always flood unused portions of the board with ground then stitch the heck out of them with ground vias, but then, I also use CPW construction. CPW makes your ground look like a much lower impedance to the circuit.

Also, you are greatly restricting your VCC to your parts with the thin lines. You have the space, why not use it? This will prevent voltage drops to your individual parts due to the resistance of the smaller VCC lines.

If I were grading your PCB, I would give it a C- to D+. You have unnecessarily left yourself open to circuit failure due to your restrictive layout.

 

First off, what is the frequency and function of the circuit? Are the traces microstrip? If so, have you ever heard of Coplanar Waveguide? Your traces look awful thin. How large is the board? When I design RF circuits, I always flood unused portions of the board with ground then stitch the heck out of them with ground vias, but then, I also use CPW construction. CPW makes your ground look like a much lower impedance to the circuit.

Also, you are greatly restricting your VCC to your parts with the thin lines. You have the space, why not use it? This will prevent voltage drops to your individual parts due to the resistance of the smaller VCC lines.

If I were grading your PCB, I would give it a C- to D+. You have unnecessarily left yourself open to circuit failure due to your restrictive layout.

Completely agree the point of using the full layer 3 as VCC. This helps the copper balance for sure.