What software are you using for your simulation? I will suggest you use the link (www.researchgate.net/publication/346054064_T-Junction_Diplexer_for_RF_Front_End_of_a_Cellular_Base_Station) to read the published paper as the full design procedure is not contained in the UA-cam video.
Thank you for video! What the signal power allow to pass through such kind of microstrip filters (diplexer)?
I drew the circuit and simulated in CST, but I couldn't get a logical result
What software are you using for your simulation? I will suggest you use the link (www.researchgate.net/publication/346054064_T-Junction_Diplexer_for_RF_Front_End_of_a_Cellular_Base_Station) to read the published paper as the full design procedure is not contained in the UA-cam video.