A Highly Linear Low Pass Filter for Low Voltage Reconfigurable Wireless Applications

This paper presents a reconfigurable and programmable analogue low pass filter for low voltage wireless applications. The proposed filter may be used for channel or band selection in multi-mode receiver front ends employing direct frequency conversion. The circuit has been synthesized using state variables and leapfrog OTA-C techniques, features programmable order, digitally variable frequency parameters and wide linear range. The fundamental OTA cell has been implemented with fully balanced second-generation current conveyors, suitable for operating with low supply voltages. Transistor level simulations based on a 180 nm digital CMOS technology have demonstrated the functionality of the design.