Q factor (for unloaded cavity resonator)

The Q factor of the cavity resonator is the ratio between the stored energy of the cavity to the power loses in the cavity.

Where V stands for volume of the cavity, A stands for Area of the cavity and S stands for skin depth of the cavity

Q factor for unloaded cavity resonator

Factors effecting Q of the Cavity

There are the following factors which affect the Q of unloaded cavity


  1. If the size of the cavity is made bigger then energy stored will be more and its Q will increase.
  2. The Q of the cavity is directly proportional to the frequency of the cavity resonator. If the cavity resonator is operating at high frequency its Q will be more.
  3. The shape of the cavity also varies its Q if cavity is in disorder shape. Its Q will be less and vice versa.
  4. The thickness of the cavity resonator will also vary its Q. if the walls of the resonator are thicker. It will observe more energy and its Q will decrease.
  5. The area of the cavity resonator will affect the Q factor. If the area is more, the more energy will observed by the conducting walls and Q will decrease.
  6. The type of conducting material of the cavity also varies the Q factor of the cavity.
  7. The internal polishing and smoothness of this polish inside the cavity also varies its Q.