Complex Permittivity Measurement

[@SalmanNaeem-xl9vu]

Can you please share the material sample you placed in the waveguide

[@vishalmistry5400]

Very nice video. What should be the size of sample piece? What should be the total length (flange to flange) of cavity for s band (2.6 to 3.95 GHz)? Please advise

[@Fan-vk9gx]

First of all, this is a resonant method. so it can only test the Er and tanD at the cavity's resonant frequency. you need to list the frequency points you are interested in. if you want to test the Er and tanD, in a frequency range. you need to use nonresonant method, such as transmission reflection method. if you use the WR284 waveguide, its width is 72mm, height is 34mm. When the length is 310mm, TE101=2.14GHz,TE103=2.54G,TE105=3.2G,TE107=3.977GHz. for the TE101 mode, its resonant frequency is too close to the waveguide's cutoff frequency, so it magnitude is too low. if you use a shorter waveguide, you will miss the resonant at 3.9GHz. if I were you, I might using three wavguide: a longer one, two identical shorter ones.first time, only use the longer one. then sandwich the longer one using the two shorter ones. in this case, can can measure the Er and tanD at the low frequency and the high frequency without changing the sample position. Hope this help you. Good luck.

[@vishalmistry5400]

Thank you for reply. Need to know Er & tanD of 99.5% alumina ceramic at 2856 MHz & 2998 MHz. What should be cavity length? 1/2 of wavelength? What should be the sample size of ceramic? Any math for cavity & sample size? Kindly advise. Thank you again

[@KlsonBob]

nice!