Abstract
A model for the external loading through a coupling hole is developed for azimuthally corrugated magnetron-type cavities with sector-shaped side resonators (grooves). It is shown that sufficiently accurate values of the external Q and dissipative rarefaction factor can be calculated with the aid of proposed analytical expressions, for the cavity geometries and modes used in practice. The obtained numerical and analytical results illustrate the main features of the complex natural frequency spectrum for the first passband. In particular, the additional possibility to rarefy the modal spectrum due to a steep variation of the external Q, which occurs when varying mode index, is revealed.