via stiching ground plane adjacent to transmission line

[Jester]

I'm not up to speed on RF layout, however I only have to provide a short 50 Ohm transmission line between a 1.5GHz transmitter module and the antenna. In the ground planes (multi-layer board) adjacent to the transmission line, how close should I place the vias that stitch the top ground plane to the inner ground plane?

 

[FvM]

What transmission line type (microstrip, stripline, coplanar)?

 

[Jester]

What transmission line type (microstrip, stripline, coplanar)?

I will use a coplanar waveguide

 

[FvM]

Coplanar waveguide, I see. The position of stitching vias is particular critical I think, but I would place them near to the inner edge. May be 5 mm repetition distance.

 

[Jester]

Coplanar waveguide, I see. The position of stitching vias is particular critical I think, but I would place them near to the inner edge. May be 5 mm repetition distance.

Thank you

 

[D.A.(Tony)Stewart]

The rule of thumb is maximum spacing of 1/8 of the wavelength but 1/10th preferred for via spacing between grounds. Via inductance increases with length/diameter ratio.