Why does my RF PCB have small holes in the ground polygon?

I ordered RF PCB design and prototype from my supplier . There are something like a hole, but it is not, on the ground surface. What is the purpose of making these holes? The PCB is inside of the E70 433NW14S LoRa module.

PCB Design
November 17, 2023

The space between copper planes can act as waveguides for RF frequencies. It makes trace impedance changes and signal losses.

To cut such waveguide effect, put vias, which is essentially a copper cylinder.

When the distances between vias are small enough compared to the wavelength, the board is like continuous copper material, instead of waveguide.

Oliver Smith

Oliver is an experienced electronics engineer skilled in PCB design, analog circuits, embedded systems, and prototyping. His deep knowledge spans schematic capture, firmware coding, simulation, layout, testing, and troubleshooting. Oliver excels at taking projects from concept to mass production using his electrical design talents and mechanical aptitude.

Oliver Smith

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