Hair pin resonator calculation
Does anyone known how to calculate the parameter for this .
For example i want to have hair pin resonator at 10 Ghz, so how can i calculate them for the lengh, the characteristic impedance( d= 0.508 mm and epsilon= 2.2)
Thank you
A hairpin resonator filter was one of the first filters I ever designed, back in 1979 for Landsat IV. We built a few resonators on Alumina, measured, then did a graph and interpolated to where we wanted.
It is a little easier now. Just do it on a planar EM analysis, any planar EM anlaysis (doing this on a volume meshing tool would be stupid, pardon my French). A single resonator (with weak coupling to an external port, so you do not disturb the resonant frequency) is an easy problem for free SonnetLite (www.sonnetsoftware.com, I work for Sonnet). You can even set up length as a parameter and do a parameter sweep. Then with a couple clicks, you have all the curves plotted for your entire parameter sweep. Just pick the one you want (or interpolate). After you go through the about 1 hour Help->Tutorial, and then read about parameters in the manual (Help->Manuals), it will take about one more hour to your final result. Actual analysis time will be a couple minutes.
For highest accuracy (again, most any planar EM analysis should do fine), analyze with one cell size, cut the cell size in half, then analyze again. The second analysis should have half the error of the first. Easy to extrapolate to nearly the exact answer. If you want to be sure, cut the cell size in half again. Whatever meshing you use, be sure you have edge meshing enabled (it is default in Sonnet), this is really important for things like resonant frequency.
I am going on travel, so it might be difficult for me to reply if there is further discussion.