Correction to "Extension of bandstop filter topology with inter-resonator coupling structures to higher-order filters" [Aug 13 403-405]

In the above-named letter [ibid., vol. 23, no. 8, pp. 403-405, Aug. 2013], incorrect versions of Figs. 4, 5, and 6(b) were published. The corrected figures are presented here. The published Figs. 4 and 5 show incorrect slot locations and two out of four slots can be interpreted as negative coupling structures, which does not support the presented theory. The correct version of the filter has the slots with the required positive values and its measured result is presented here [Fig. 6(b)]. To conclude this letter, the authors would like to point out that the above errors do not affect the presented theory in [1].