tuned resonating cavity

tuned resonating cavity

[¦tünd ′rez·ən‚ād·iŋ ‚kav·əd·ē]
(electromagnetism)
Resonating cavity half a wavelength long or some multiple of a half wavelength, used in connection with a waveguide to produce a resultant wave with the amplitude in the cavity greatly exceeding that of the wave in the waveguide.