Comment on ´Realisation of 2D analogue filters´

For original paper see Venkateswarlu and Eswaran, ibid., vol.25, no.24, p.1647-8 (1989). In the original paper the problem of 2-D filtering is reduced to the problem of a multiport network design. It is shown that the multiport network can be realised using N integrators and a summer, where N is the order of the filter. The deficiency of the filter in the presented configuration is its high sensitivity, because of the direct realisation of the transfer function coefficients as multipliers in the network. The present author points out that the multiport network considered can be realised as a gyrator-capacitor network, hence the low sensitivity realisation can be achieved.