Design of odd n th‐order elliptic high‐pass filters employing OTRAs

Abstract

Two new analytical synthesis methods are proposed for synthesising an nth odd-order elliptic high-pass (HP) filter using operational trans-resistance amplifiers (OTRAs). The analytical synthesis scheme is based on the assumption of infinite trans-resistance R m for the OTRA. The H-spice simulations of the realised elliptic third-order HP filters show that the realisation using less number of OTRAs has a performance better than that which uses more number of OTRAs, as is to be expected in view of the assumption that R m is infinite, when in fact it is finite in practice. However, it is shown that by slightly adjusting a single resistor, the amplitude-frequency response can be made close to the theoretical response.