Multiple-pole resonator filter

A packaged module for radio-frequency application, comprising:

• a packaging substrate configured to receive a plurality of components;
• a filter circuit implemented on the packaging substrate and including a first coaxial resonator in a first orientation and having an input on a first side of the filter defined by N coaxial resonators, an N-th coaxial resonator in the first orientation and having an output on the first side of the filter, a second coaxial resonator in a second orientation opposite the first orientation to form a first interdigitation with the first coaxial resonator, an (N−1)th coaxial resonator in the second orientation to form a second interdigitation with the N-th coaxial resonator, and one or more coaxial resonators coupled between the second and (N−1)th coaxial resonators, such that the N coaxial resonators have slot coupling between adjacent ones of the N coaxial resonators;
• and
• an input connector coupled to the input of the first coaxial resonator, and an output connector coupled to the output of the N-th coaxial resonator.