At frequencies below the self-resonant frequency, a capacitor can be considered as a pure capacitor Cs with an equivalent series resistor RS, both elements being shunted by a pure resistor Rp. Low series resistance of RS, usually below 1 ohm is prevailing the very high resistance of Rp (above 106 MΩ) in microwave applications.
Equivalent series resistance (Rp) is essentially comprised of :
• the intrinsic series resistance of electrodes and terminations, which is a few tens of milliohms maximum,
• the resistance inherent to material atomic structure losses.
Dissipation in capa-citors first occurs in the dielectric where the energy is stored and transferred. Quality factor Q, in inverse
proportion to Tg δ, is determined by the ratio of stored energy to dissipated energy per cycle.