matching diaphragm

matching diaphragm

[′mach·iŋ ′dī·ə‚fram]
(electromagnetism)
Diaphragm consisting of a slit in a thin sheet of metal, placed transversely across a waveguide for matching purposes; the orientation of the slit with respect to the long dimension of the waveguide determines whether the diaphragm acts as a capacitive or inductive reactance.