MULTIMODE REJECTION FILTER FOR SLOT WAVEGUIDE Russian patent published in 1997 - IPC

FIELD: devices for heating dielectrics, including microwave ovens. SUBSTANCE: filter has at least one set of weakly coupled series LC circuits incorporating parts with lumped parameters; it is at least partially placed in slot waveguide formed by part of multimode cavity body of device for heating dielectrics by electromagnetic energy (such as domestic microwave oven) provided with charge- discharge port and by periphery of door block around this port. At least one LC circuit of one of slot waveguide walls is used as one of capacitor plates (concerning dielectric heating device, cavity body, or door block). LC circuits of at least one set of coupled circuits are tuned to different frequencies near frequency of wave being filtered. EFFECT: improved protection of cavity against leakage of electromagnetic waves; reduced size of filter and, hence, size of device incorporating it; enlarged frequency band of filtered waves, improved operating reliability of filter. 9 cl, 6 dwg