Study of cavity impedance between two plane on PCB

[rdpdo2002]

Hello,

I would like to calculate the impedance between the two plane of a PCB when electromagnetic fieds expanse in the dielectric to illustrate how the cavity resonate.

My aim is to put some GND via to illustrate the resonnance changing.

I tried to make a wave port on top and on bottom to get S parameter but got error because plane on bottom is perfect conductor.

So I am trying to use field calculator to estime impedance. I first try to get capacitance using Q=CV ; I can have Q on top and Q on bottom but to get Voltage across top and bottom I need to integrate E along Z between the two planes... but for each line on the volume... I don"t know how to do ??

Do you have a guideline to do this ?

Thanks you !

 

[D.A.(Tony)Stewart]

I presume this is like a patch resonant antenna except for fringe effects. Gap C can be computed with plane L.

 

[D.A.(Tony)Stewart]

Planar capacitance depends on gap, area and dielectric constant between conductors.

https://study.com/skill/learn/how-to-calculate-the-capacitance-of-a-parallel-plate-capacitor-of-given-its-geometry-explanation.html

Planar inductance of a square area has the same near zero inductance regardless of its size. But then at wavelengths > 10% path length with gap capacitance it becomes a dielectric resonator antenna.

https://its.ntia.gov/umbraco/surface/download/publication?reportNumber=98-344.pdf