The
Mica capacitor uses
mica as the
dielectric material.
Mica is a
transparent mineral, that is
easy to
split into
thin plates. The
mica plates is given
silver electrodes
and than
stacked to get the wanted
capacitance. It has
exelent characteristics like low
loss and high
stability
and can
compete with the best
plastics. the downsides
is high price and large size. Because of this
mica has been replaced by
plastic film capacitors in many
applications. But
mica
capacitors is still much used in
high frequency circuits
due to high
temperature and
frequency stability.
Mica capacitors are
available in the
range 1pF to
250nF and for
voltages up to about 50kV.