... can be its main parameters, including: the resonant frequency Fs, the anti-resonant frequency Fp, half-power point of F1 and F2 ... L1, free capacitor CT, the free dielectric constant, mechanical quality factor Qm, electromechanical coupling coefficient Keff , Kp, K31, K33, and piezoelectric ... low cost, simple, user-friendly features such as software. ultrasonic frequency impedance analyzer