[moved] Microstrip filter design advantages over RLC filter

Dear all:
Kindly i need to answer the following question as i tried to get the best answer to it but i could not why I use micro striplines or transmission line to implement the Filter in High frequency(microwave frequency) instead of lumped element

thank you in advance

You stsand a better chance of getting a physically realisable circuit with transmision lines than wiht liumped components.
Try designing a few simple filters and see what values you get. Ther eis plenty of free software available if you don't want to use a book and tables.