insertion losses in cavity filter

Dear cavity filter experts,

Please discuss possible solutions for the reduction of insersion loss of a cavity filter. There is no dielectrics in the cavity.

Thanks,
tommy

Choose the right resonator mode for highest Q (see any emag textbook), and silver plate the whole thing.

you are right, but the two things you mentioned are commonly used ways. Are there any other tricks?

thanks.

Reduce the order of filter

Increase ground plane spacing.

Increase dimension of the cavitys, the bigger cavity must be reduce insertion loss.

Some cutting edge research using this new metal:

http://james-camerons-avatar.wikia.com/wiki/Unobtanium

Making the filter out of this will give passband gain!