Comments on "Waveguide-to-coupled fin-line transition in a Ka band" [and reply]

For original paper see D.B.Sillars, Proc. Inst. Elec. Eng., vol.134, pt.H, no.3, pp.229-33 (1987). The authors of the above letter may be interested in work that was previously carried out to excite both odd and even modes in coupled-slot fin-line circuits. A similar transition from microstrip into the even mode coupled-slot fin-line to that proposed in the above letter was developed for Ka band, particularly over 28 to 40 GHz, with levels of performance achieved similar to that reported in the above letter. This transition was primarily developed as part of an investigation into the nonreciprocal effects of loading coupled-slot fin-line circuits with longitudinally magnetized ferrite slabs.