A Novel Versatile Current-mode Universal Biquadratic Network and its applications

Abstract

This article presents a novel current-mode universal biquadratic network providingstandard transfer functions. The principal elements of proposed network are OTAs. Thefeature of this network is that the pole frequency quality factor can be orthogonally adjustedvia input bias currents. Besides performing as a universal filter, with an appropriatecondition, the proposed network can function as a quadrature oscillator without changing itscircuit topology. The oscillation frequency and amplitude can be independently controlledvia input bias currents. With the above major advantages, the proposed oscillator can beapplied to provide AM/ASK that is widely used in communication systems. The PSPICEsimulation results are depicted. The given results agree well with the theoreticalanticipation, where the maximum power consumption is 3.03mW at ±1V supply voltages.In addition, the circuit description is very simple, consisting of merely 4 OTAs and 2grounded capacitors. Each OTA provides cutoff frequency up to 40.19MHz. Without anyexternal resistors and using only grounded elements, the proposed circuit is very easy tofurther develop into an IC form for operating in a battery-powered portable wirelesscommunication system equipment.