Some observations concerning the methods of filter/oscillator realization using the concept of FDNR

It has been shown that the method of converting a passive RLC low-pass (LP) filter into an inductorless filter using the concept of frequency-dependent negative resistance (FDNR) is equivalent to first applying the low-pass-to-high-pass (LP → HP) transformation and then the RC:CR transformation on the LP filter. Also, the RLC model of an active-RC oscilator and the corresponding RCD model derived from this through Bruton´s transformation are RC:CR transforms of each other. The latter observation suggests that many novel oscillator circuits can be generated from existing ones through RC:CR transformation.