Design of Band-Pass Filter Based on Active Capacitance Circuit and Tunability with Neural Network

In this research، active capacitance circuit and the feature of negative resistance are analysed in details. Also، a new active filter is presented based on active capacitance circuit. For simulations، we used MATLAB and Advanced Design System (ADS). proposed active filter (RF) is a narrow band filter. The results of simulation shows some aspects of sustainability and low noise feature. The circuit has negative resistance at frequency range of 2-7 GHz، in which negative resistance is adjusted with neural network. The central frequency is 5. 50 GHz، and band width is 278 MHz. In the central frequency the gain is 1 dB and quality factor (Q) is 24. The active filter noise figure in central frequency is 1. 51 dB. Generally، K factor (stability factor) is greater than one meaning circuit is completely stable in the considered frequency range. The results from regulations with neural network has an error less than 1% in central frequency.