How to design the vertical transition between microstrip

[burton]

Now I am designing the vertical transition between microstrip in LTCC.Which is the better, interconnect by vertical via or coupling by aperture ?How can I design them properly?

 

[IICCEE]

yon must model the transition in 3D em software.
In early,some one model this by CST,and find some filter behaviour in high friquency.