Re: filter types between antenna and LNA?

where can I find good design formula and calculations or software for Helical Filter at VHF(100~200 MHZ)?

in LC filter design for pre-LNA applications what filter type and order is normally used?What is the min value of Q for L and C ?

http://tonnesoftware.com/helical.html

http://www.comnav-eng.com/dnload.asp

"Filters With Helical and Folded Helical Resonators" by Peter Vizmuller, Artech House, ISBN 0890062447

I think most of the filter for the front end system is the cavity filter assuming not very wideband.

that frequency range may be too low for microstrips.
Lumped elements should work fine.