Patent ID: 6307449
Filing Date: 2001-10-23
Classification: H01P

Abstract:
A filter comprising:a substrate;connection means for providing electrical connection;a filter circuit on a top surface of said substrate including at least a resonator electromagnetically resonating at a resonance frequency at a microwave band and a millimeter wave band, for filtering an input signal from said connection means through said resonator and outputting the filtered signal through said connection means;a metal box including a top plate confronting said top surface and said filter circuit, side walls, and a bottom plate, for containing and supporting said substrate and filter circuit, a portion of said side walls supporting said connection means, wherein a first portion of said input signal is transferred through said filter circuit and a second portion of said input signal is transferred through a portion of said metal box in the wave-guided mode, said second portion providing a spurious characteristic of said filter, an inside surface of said top plate having a shape other than a plane to control the spurious characteristic, wherein said top plate has a thickness between a top surface thereof and said inside surface and said thickness successively increases and then, successively decreases in a direction.