about the microstrip filter

hello,
i designed a Edge-Coupled half wave filter used ANSOFT Serenade.
i found the frequency always lower in fact, but also the loss is more,
Who can tell me what happened?

What were your ecpectations ? what did you get 'em?

after you simulate with ansoft senrenda,you must simulate it with Em simulator such as ensemble

thanks,
i'm only analysed in serenade.
but i'm a beginner,i don't know how to use Ensemble.
Could you tell me how can i get a good filter if i only use serenade?