Hello all. I am conducting a simulation based report on resonant inductive coupling. I intend to calculate power transferred as a function of input frequency. For this I used the formulae for self resonant frequency and calculated a SRF of 3.283MHz using 10mH, 235pF and 0.25Ohms as my values for the RLC circuit. Using LTspiceXVII I created a schematic and the frequency analysis verified my theoretical value of 3.283MHz. However when I created another identical series RLC circuit ( with 50Ohms load) and coupled it together using the statement ( K L1 L2 1). However the frequency response showed a different frequency of 2.3215MHz this time. This resonant frequency is equal to a identical circuit but double the inductance (20mH). The mutual inductance should be equal to M = K ( sqrroot(L1*L2) ).
Why does this phenomena occur?
Hence I decide to set the coupling coefficient to value of 0.5. Setting this created two peaks with current plotted on the linear X axis. According to self resonant frequency should not there be one peak?. First peak occurred at 2.68MHz at a current of 231mA and the second at 4.65Mhzat a current of 209mA.
I have attached the LTSPICE file below. Your help is greatly appreciated. Thank you so much.
Why does this phenomena occur?
Hence I decide to set the coupling coefficient to value of 0.5. Setting this created two peaks with current plotted on the linear X axis. According to self resonant frequency should not there be one peak?. First peak occurred at 2.68MHz at a current of 231mA and the second at 4.65Mhzat a current of 209mA.
I have attached the LTSPICE file below. Your help is greatly appreciated. Thank you so much.
Attachments

1.4 KB Views: 7