A method for tuning the center frequency of embedded microwave filters

摘要

A method of tuning the frequency response of filters embedded in or formed on a ceramic substrate, such as but not limited to a low temperature co-fired ceramic substrate (LTCC), by re-firing a previously fired LTCC substrate to a temperature which is greater by a predetermined, relatively small, amount than that of the temperature produced during the original firing profile of the substrate so as to change the dielectric constant of the substrate, and thus cause a desired shift in the filter's frequency response.