Hi! I sent a post showing how to measure resonance and self resonance and I calculated all parameters of a resonant circuit using almost any VNA. The self resonance is the parallel resonance when you connect a series LC to VNA port. The resonance conditions becomes when the imaginary part of S11 becomes zero at a determined frequency¡ in the attached picture there are both the serial resonance frequency on marker 1 and parallel on marker 2. Parallel resonance result of parallel connection between L and Cp with is the parasitic capacitance , this is the self resonance frequency. The method is absolutely sensitive to calibration I recommend very good standards.
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I don?t know about your application but self resonance are very unstable depending on dielectric properties of the form ( many times varies with temperature and moisture) and changes every time. The best is to have this resonance frequency very far from working frequency using a very well known capacitor. If you need to know the self resonance to have the value of Cp parasitic capacitance its a very good method but there are other methods that gives it value at the work frequency. Cp frequency dependent. I showed a method to do it on other post , this is derived from a procedure with Q-meter. If you need more details just let me know more about your interest. Ing. Patricio A. Greco Laboratorio de Calibraci¨®n ISO 17025 AREA: RF/MW Gral. Mart¨ªn Rodr¨ªguez 2159 San Miguel (1663) Buenos Aires T: +5411-4455-2557 F: +5411-4032-0072 www.servicios-electronicos.com.ar On 10 Dec 2024, at 15:09, jskinner58 via groups.io <jskinner58@...> wrote: |