Patent ID: 6498550
Filing Date: 2002-12-24
Classification: H01P

Abstract:
A filter, comprising:a first conductive layer positioned in a substrate of semiconductor material to form a cavity and having a first surface for reflecting an electromagnetic wave; a dielectric block of a dielectric material having a relative permittivity substantially greater than one and disposed adjacent to the first conductive layer and completely filling the cavity, for propagating the electromagnetic wave a first distance to the first surface of the first conductive layer to determine a resonant frequency of the filter, the first distance being determined by size of the dielectric block and established to be equal to one-fourth of a wavelength of the resonant frequency of the filter; a second conductive layer overlying the substrate and the dielectric block and formed with a first opening and a second opening overlying the dielectric block to thereby have first, second and third portions of the second conductive layer, the first opening being defined by the first and second portions and coupling the electromagnetic wave as an input, the second opening being defined by the second and third portions and coupling the electromagnetic wave as an output; a first dielectric overlying the first portion of the second conductive layer and filling the first opening; a second dielectric overlying the third portion of the second conductive layer and filling the second opening; a first conductor overlying the first dielectric, wherein the first portion of the second conductive layer, the first dielectric and the first conductor jointly form a first transmission line for collectively inputting the electromagnetic wave; a first conductive via connected between the first conductor and the second portion of the second conductive layer to terminate the first transmission line in a first short circuit adjacent the first opening; a second conductor overlying the second dielectric, wherein the third portion of the second conductive layer, the second dielectric and the second conductor jointly form a second transmission line for collectively outputting the electromagnetic wave; and a second conductive via connected between the second conductor and the second portion of the second conductive layer to terminate the second transmission line in a second short circuit adjacent the second opening to improve coupling from the dielectric block through the second opening to the second transmission line.