Ceramic filter with channeled features to control magnetic coupling

摘要

A ceramic filter (120) with at least one transmission zero is disclosed. The filter (120) has a filter body comprising a block of dielectric material and having top (110), bottom (112), and side surfaces, and having metallized through-holes extending from the top to the bottom surfaces defining resonators. The surfaces are substantially covered with a conductive material defining a metallized layer. The top surface (110) is uncoated. The filter (120) can also include input-output pads ( 104, 106). The bottom surface (112) has a channel (108) defining a magnetic coupling between the resonators. The channel configuration and placement can vary depending on the desired frequency response.