Low temperature co-fired ceramic (LTCC)-coupled stripline resonator filters for use as bandpass filters are implemented with combline topology or with interdigital topology. The filter bandwidths range from about 0.3 GHz to less than 1 GHz with frequency operation of about 0.1 GHz to 100 GHz. The filters have vias between adjacent resonators with via spacing significantly smaller than the wavelength at the filter center frequency to generate electrical walls between adjacent resonators resulting in coupling reduction for narrowband filter implementation. A narrowband filter transformer loading structure launches the input and the output to the first and last resonators.