
16 Analog Electronics
In radio-frequency circuits working at frequen-
cies up to hundreds of megahertz and beyond,
capacitors in the range 1 to 1000 pF are widely
employed. These commonly use a thin ceramic
disc,
plate or tube as the dielectric, with metallized
electrodes. The lower values, up to 100 pF or so,
may have an NPO dielectric, i.e. one with a low,
nominally zero, temperature coefficient or capaci-
tance. In the larger values, N750, N4700or N15000
dielectrics may be used (N750 indicates a tempera-
ture coefficient of -750 parts per million), and disc
ceramics for decoupling purposes with capaci-
tances up to 470 nF (0.47 μΡ) are commonl ...