Frequency tunability of fractance device based on OTA-C

This paper presents the realization of fractance device by using an approximating function. From this function, we can obtain the characteristic of fractional passive element with constant phase at specific bandwidth. The approximating functions can be realized by RC network. Unfortunately, the RC passive network is not suitable for integration and lack of interesting features as well as frequency tuning. Hence, this paper proposes the realization of fractional device based on OTA-C without any resistor. The rational functions were simplified to series expansion that can realize by low-complexity OTA-C. Due to the biomedical applications, the device order of 0.507 and 0.766 are given in this paper. The results show the magnitudes and phases in agreement with the theory and also approximating functions. Frequency tunability feature is obtained from 100Hz to 10kHz by adjusting IB from 1μ A to 100 μ A. PSpice simulation results are carried out to confirm with the theory.