interdigitalCapacitor RF PCB Tool

I am trying to use RF PCB Tool on Matlab online and want to analyse an interdigit with 10 fingers or more.

The 'interdigitalCapacitor' function allows me to do so, but the size of substrate doe not change accordingly, i.e., the width and length of the substrate below doesnot expand when I increase the number of fingers greater than 4 (the default value) and the additional fingues are left hanging outside the substrate.

Could some one suggest how to change the dimension of substrate?

Answer 1

[Srujana]

Hi Rahul,

I understood that you are trying to build an interdigital capacitor with 10 fingers . when you changed that in “show” you observed some of the fingers are outside the substrate which is not a practical case.

In interdigital capacitor object, we have a property called “GroundPlaneWidth ” which will allow you to change both substrate and ground plane width.

obj = interdigitalCapacitor;
obj.NumFingers = 10;
obj.GroundPlaneWidth = 0.0060;
show(obj)

This is an expected behaviour for any object in RFPCB Toolbox where it will retain its default values if a user does not specify it. And we provide the user flexibility to change these values.