Piltyay, S.I. and Dubrovka, F.F. 2013. Eigenmodes analysis of sectoral coaxial ridged waveguides by transverse field-matching technique. Part 1. Theory. Visnyk NTUU KPI Seriia - Radiotekhnika Radioaparatobuduvannia. 54 (Nov. 2013), 13-23. DOI:https://doi.org/10.20535/RADAP.2013.54.13-23.