Постульга, А. С., & Мартынюк, С. Е. (2014). Influence of the directional coupler’s parameters on the characteristics of Butler matrix 4×4. Visnyk NTUU KPI Seriia - Radiotekhnika Radioaparatobuduvannia, (57), 43-50. https://doi.org/10.20535/RADAP.2014.57.43-50