Novel Results on the Large-Signal Dynamic Admittance of $p-n$-Junctions
  Recent theoretical results obtained by Barybin and Santos have suggested that the dynamic admittance of the $p-n$-junction is proportional to the modified Bessel function of the first kind which depend on an amplitude of ac signal. This result extends the conventional theory usually encountered in known papers and textbooks. In this letter, some experimental results are presented to confirm our theoretical prediction. The measurements were performed with a lock-in amplifier, using a low noise operational amplifier. Two types of the $p-n$-diodes were employed to check our theory: 1N914B diode, typically used for high-frequency applications, and 1N4007 diode, typically used in power supplies. Experimental results are consistent with the theoretical ones if a fitting parameter allowing for generation--recombination processes in the depletion layer is taken into account. 
Edval J. P. Santos and Anatoly A. Barybin