Development of a Digital Universal Filter Bank

• Main Author: Larsson, Mats
• Format: Others
• Language: English
• Published: Uppsala universitet, Signaler och System 2016
• Online Access: http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-307929

This is a master's thesis project, which is a part of the Master Programme in Electrical Engineering at Uppsala university. When developing a product or performing measurements, it is sometimes necessary to remove some content of a signal. This might be due to an interfering source that has to be filtered out, or that only a specific frequency interval is of interest. In such a case, it would be practical if a universal frequency selective filter was available and easy to use. In this thesis, a platform for implementing different frequency selective digital filters is developed. Through a user interface, parameters such as sampling frequency, filter order, type of filter and cutoff frequencies are set by the user. This provides a platform which is easy to configure in order to run one or multiple IIR or FIR filters in various constellations. By combining different filters, a wide variety of frequency responses can be obtained. A prototype is constructed, which allows the user to connect up to two input signals and retrieve up to two output signals. The filter bank is programmed in C and implemented in a 32-bit microcontroller, base on the ARM architecture. To get a reliable prototype, a printed circuit board is designed and manufactured. To protect the electronics from external stress, a cover is designed and 3D-printed. The filter design algorithms and the algorithm used when running the filter bank gives satisfying results. The capacity of the filter bank can be increased by refining the filtering algorithm. By improving the hardware, noise generated by the electronics can be decreased. The filter bank has a really good potential to become a very useful tool.