A multi-resonator filter comprising: a) a signal input terminal; b) a signal output terminal; and c) a plurality of resonator components comprising an input resonator component coupled to the signal input terminal, an output resonator component coupled to the signal output terminal, and at least one intermediate resonator component (106b, 126c, 126d, 106e) coupled between the input resonator component and the output resonator component; wherein the input resonator component, output resonator component and the at least one intermediate resonator component (106b, 126c, 126d, 106e) are arranged in a sequence to define a signal path between the signal input terminal and the signal output terminal; the at least one intermediate resonator component (106b, 106c, 106d, 106e) comprises at least one multiple resonator component (126c, 126d), each multiple resonator component (126c, 126d) including a pair of individual resonators (126c1, 126c2) coupled in parallel, wherein each individual resonator in a given pair of individual resonators (126c1, 126c2) has the same resonant frequency; and characterized in that each of the input resonator component, the output resonator component and the at least one intermediate resonator component (106b, 106c, 106d, 106e) comprises a rectangular iris waveguide configured to transmit electromagnetic signals. a) a signal input terminal; b) a signal output terminal; and c) a plurality of resonator components comprising an input resonator component coupled to the signal input terminal, an output resonator component coupled to the signal output terminal, and at least one intermediate resonator component (106b, 126c, 126d, 106e) coupled between the input resonator component and the output resonator component; wherein the input resonator component, output resonator component and the at least one intermediate resonator component (106b, 126c, 126d, 106e) are arranged in a sequence to define a signal path between the signal input terminal and the signal output terminal; the at least one intermediate resonator component (106b, 106c, 106d, 106e) comprises at least one multiple resonator component (126c, 126d), each multiple resonator component (126c, 126d) including a pair of individual resonators (126c1, 126c2) coupled in parallel, wherein each individual resonator in a given pair of individual resonators (126c1, 126c2) has the same resonant frequency; and characterized in that each of the input resonator component, the output resonator component and the at least one intermediate resonator component (106b, 106c, 106d, 106e) comprises a rectangular iris waveguide configured to transmit electromagnetic signals. wherein the input resonator component, output resonator component and the at least one intermediate resonator component (106b, 126c, 126d, 106e) are arranged in a sequence to define a signal path between the signal input terminal and the signal output terminal; the at least one intermediate resonator component (106b, 106c, 106d, 106e) comprises at least one multiple resonator component (126c, 126d), each multiple resonator component (126c, 126d) including a pair of individual resonators (126c1, 126c2) coupled in parallel, the input resonator component, output resonator component and the at least one intermediate resonator component (106b, 126c, 126d, 106e) are arranged in a sequence to define a signal path between the signal input terminal and the signal output terminal; the at least one intermediate resonator component (106b, 106c, 106d, 106e) comprises at least one multiple resonator component (126c, 126d), each multiple resonator component (126c, 126d) including a pair of individual resonators (126c1, 126c2) coupled in parallel, wherein each individual resonator in a given pair of individual resonators (126c1, 126c2) has the same resonant frequency; and characterized in that each of the input resonator component, the output resonator component and the at least one intermediate resonator component (106b, 106c, 106d, 106e) comprises a rectangular iris waveguide configured to transmit electromagnetic signals.