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 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 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 comprises at least one multiple resonator component , each multiple resonator component 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 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 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 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 comprises at least one multiple resonator component , each multiple resonator component 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 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 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 comprises at least one multiple resonator component , each multiple resonator component 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 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 comprises at least one multiple resonator component , each multiple resonator component 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 comprises a rectangular iris waveguide configured to transmit electromagnetic signals. <EOS>