Effect of frequency on dielectric constant and thus capacity of parralel plate CAP

Status
Not open for further replies.

ark5230

Advanced Member level 3
Joined
Jun 29, 2009
Messages
862
Helped
163
Reputation
324
Reaction score
140
Trophy points
1,323
Location
India
Activity points
6,187
I am worried about the effect of frequency on dielectric constant and thus capacity of parralel plate CAPACITOR.
C = KA/d
C is capacity, K is dielectric constant of the medium between the two plates, A is area of the parallel plates and d is the spacing between them.

Is this relation independent of frequency or this formula can be used at all frequency by using corresponding value of K at that frequency.
 

I think that dielectric constant (in dielectrics with no mobile
charge) is relatively frequency-independent, and error terms
in capacitor value vs frequency can be ascribed to series R,
L and shunt C (to where?) elements lumped into the
measurement.

In a RF IC PDK you would see capacitor elements with
R, L, C parasitics embedded, at least covering what lies
within the physical extents of, and respond to geometry
of, the capacitor cell.

Losses vs frequency is a different matter but properly
measured these ought not to affect C itself.
 

Actually, In addition to the frequency related concern I was trying to find out how do I calculate the capacitance of a capacitor with two layers of the dielectric as shown in the figure with two different dielectric constants.
 

Attachments

  • Capacitor.bmp
    150.1 KB · Views: 86

Status
Not open for further replies.
Cookies are required to use this site. You must accept them to continue using the site. Learn more…