about hagh pass filter,the highest passband frequency

I want to design a highpass filter.the pass band need to be 6G-12.75G
There maybe three choices:microstrip ,coaxial line,stripline
As I know ,when the frequency is increasing, high modes will appear in
the transimission line, this is the cause for deterioration in the high frequency
end.
I know that coaxial line's high mode will be higher than those of microstrip and
stripline,but coaxial line high pass filter will have more difficulty in fabricate and
tuning though it supports higher power handling.
stripline high pass filter is not very easy to tune.and will be worse in the high freqency band than coaxial's
microstrip may be easy to fabricate and tune but it's power handling is not high
and the high frequency band will be worse.
so ,will any experts give me some advices on the design?thanks.

liuyun

HOW the high pass filter used for ? the power handling needed?
the high mode can be estemited and by properly design,can be out of the passband i think.