Electrical noise in low-pass FDNR filters

The electrical noise performance of generalized impedance converter (GIC) low-pass ladder structures is derived. The concept of frequency-dependent negative-resistance (FDNR) elements has allowed low-sensitivity high-order low-pass ladder structures to be realized directly from the corresponding LC prototype. The electrical noise appearing at the output of the low-pass FDNR realization is derived for the equiterminated low-pass Butterworth realization, and it is shown that the output noise power spectral density may be obtained from a suitable noise model of the GIC. Experimental verification of the output noise spectral density is given.