Investigation of Performance of Passive and Active Low Pass, High Pass, and Band Pass Filters

Ng, Yong Jie (2023) Investigation of Performance of Passive and Active Low Pass, High Pass, and Band Pass Filters. Final Year Project (Bachelor), Tunku Abdul Rahman University of Management and Technology.

Text Full Text -Ng Yong Jie.pdf Restricted to Registered users only Download (3MB)

Abstract

Filters circuits are widely used in communication, instrumentation, and electronics systems, particularly in image and signal processing systems. It is critical to look into the performance of these filters. The issue with this project is that there has not been much work done to evaluate the filters performance. Software-wise, this project requires the use of LabVIEW, MATLAB, Multisim, Microsoft Excel and PC-Basic. The hardware requirement includes two frequency generators, an oscilloscope and electronic components such as resistors and capacitors. A few filter circuit designs are set up and tested with simulation software and appropriate hardware. The filter characteristics obtained from software simulation and hardware tests are comparable. The performance of each different type and order of filters had been reviewed after hardware tests. The results of these tests revealed that active filters exhibited better signal-to-noise performance compared to passive filters. Furthermore, the research demonstrated that second order filters outperformed first order filters in terms of signal-to-noise performance. This research also evaluated two different circuit designs for second order filters, namely cascaded and with a voltage follower circuit. The results indicated that the higher order design with voltage follower circuit exhibited better SNR performance than the cascaded design. The results shows that a narrow bandwidth filter provides better performance than a regular active band pass filter when there is a need for a single frequency or a narrow range of frequencies in the case of a band pass filter.