开云体育

Measuring the 2GHz cavity filter

#spectrum_analyzer

Erik Kaashoek All Messages By This Member #509 To complete the building I measured the S21 of the cavity filter First the pass band As the home build GHZ VNA does not have any shielding the dynamic range is rather limited but the -3dB bandwidth?is about 4MHz and the loss is -3dB. From other measurements its clear the suppression of the image at 21.4MHz offset is good enough. Certain cavity filters do have harmonic modes that will allow 2nd or higher order harmonics to pass. I can only measure S21 till 4.3GHz so here is a wide sweep. The peak at 4.3GHz is an artifact of my SW, its not there when you zoom in. So interdigital filter instead of a comb filter does indeed suppress?the harmonics modes The S11 measurement shows there is still some room for improvement but for now I'm happy.
Satish Chandorkar All Messages By This Member #511 Hello Erik Can you place the complete project of your home brewed Ghz VNA analyzer here on the group That is circuit diagram, and the required boards and also the software or link for it. Many of us do lack in such a good home brewed equipment and can not afford commercial ones being very costly Satish VU2SNK toggle quoted message Show quoted text On Sat, Nov 30, 2019 at 2:08 PM <erik@...> wrote: To complete the building I measured the S21 of the cavity filter First the pass band As the home build GHZ VNA does not have any shielding the dynamic range is rather limited but the -3dB bandwidth?is about 4MHz and the loss is -3dB. From other measurements its clear the suppression of the image at 21.4MHz offset is good enough. Certain cavity filters do have harmonic modes that will allow 2nd or higher order harmonics to pass. I can only measure S21 till 4.3GHz so here is a wide sweep. The peak at 4.3GHz is an artifact of my SW, its not there when you zoom in. So interdigital filter instead of a comb filter does indeed suppress?the harmonics modes The S11 measurement shows there is still some room for improvement but for now I'm happy.
Erik Kaashoek All Messages By This Member #512 Satish SW (both PC and Arduino)? HW description incl schematic of the mixers?/g/HBTE/files/SimpleVNA Will do an update as the current documentation and Arduino SW on github does not yet include the ebay ADF4351 modules, only for the SI5351 module The principles are the same. But it will never be a simple kit with fool proof documentation.?

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