Bandstop Filters with Minimum Through-Line Length

Systems and methods are provided for creating higher order microwave bandstop filters with total through-line length of significantly less than one-quarter wavelength at the filter center frequency. The mixed electric and magnetic field coupling bandstop filter topologies provided by embodiments of the present disclosure can be used to reduce the size, weight, and throughline insertion loss of microwave bandstop filters. In an embodiment, if the relative field strengths are intelligently designed for each coupling structure, effective phase offsets can be produced between resonators along the through line. These phase offsets can be used to absorb some or all of the length of the λ/4 inverters between resonators.