Realisation of CBTA Based Current Mode Frequency Agile Filter

In this paper, current mode frequency agile filter based on Current Backwards Trans-Conductance Amplifier (CBTA) is proposed. The proposed filter provides high tunability and agility. The internal structure of CBTA is modified to produce two low pass responses simultaneously. Using the modified CBTA schematic, Low pass controlled low pass, Low pass controlled high pass and High pass controlled low pass agile filters are proposed. These responses are functionally verified using PSPICE simulations. The simulations are performed using the PR100N (PNP) and NR100N (NPN) transistors model of the bipolar arrays ALA400 and filter parameters with variation in external gain is examined.