Memristors have been at the forefront of nanoelectronics research for the last few decades, offering a valuable component to reconfigurable computing. Their attributes have been studied extensively along with applications that leverage their state-dependent programmability in a static fashion. However, practical applications of memristor-based alternating current (ac) circuits have been rather sparse, with only a few examples found in the literature where their use is emulated at higher frequencies. In this work, we study the behavior of metal-oxide memristors under a noninvasive ac perturbation in a range of frequencies, from 103 to 107 Hz. Metal-oxide memristors are found to behave as RC low-pass filters and they present a variable cut-off frequency when their state is switched, thus providing a window of reconfigurability when used as filters. We further study this behavior across distinct material systems, and we show that the usable reconfigurability window of the devices can be tailored to encompass specific frequency ranges by amending the devices' capacitance. This study extends current knowledge on metal-oxide memristors by characterizing their frequency-dependent characteristics, providing useful insights for their use in reconfigurable ac circuits. © 1963-2012 IEEE.