Complex conjugate poles implementation in discrete-time charge-domain filters

A discrete-time charge-domain filter is proposed, which can realise complex conjugate poles in the transfer function of the filter. By employing a second transconductance in the feedback path of a second-order infinite impulse response charge-domain filter, it is proved that the filter topology is capable of implementing complex poles. This method makes charge-sampling filters more efficient in designing frequency-domain filters where they can be used to synthesise any type of filter structures such as Butterworth, Chebyshev and so on.