Comments on "Microwave filters of parallel-cascade structure"

For the original article see ibid., vol. 42, no. 7, p. 1360-7 (1994). In the aforementioned paper Osipenkov and Vesnin show how a parallel connection of two four-poles can be used to implement a microwave filter. Here the commenters point out that the four-poles was incorrectly termed four-port networks by the authors and go on to show that certain conditions need to be satisfied in the realisations presented.<>