2025

Circuits, Systems, and Signal Processing

Journal year: 2025 | Journal number: ?

scientific article

english

EN The design of precise filters based on lossless prototype circuits has been developed for a long time, and the application of LC ladder structures for that purpose is a well known technique. Such structures are two-port networks with transfer functions being the rational functions in the domain of the complex variable s. Hardware filter implementations, of both continuous and discrete time, are realized as integrated circuits in technologies such as operational transconductance amplifiers plus capacitors (OTAC), switched capacitors (SC), switched currents (SI), as well as digital filters. This work presents gyrator-capacitor (gC) circuits, as prototype ones, in which the particular capacitances can have assigned the complex variables s in various dimensions. Such an approach allows eliminating the lack of appropriate methods of multi-dimensional stable infinite impulse response (IIR) filter synthesis. The work describes algorithms and computer tools resulting from the elaborated methods. There are presented examples of three-dimensional (3-D) IIR filters for video processing, designed with the use of tools worked out. Realized in this way smooth and sharp filters for videos are described in the paper. The operation of the filters is illustrated by results of computer simulations of video filtering and implementation of such filters in FPGA is also presented. This hardware implementation shows that real-time video filtering with the use of these filters is achievable. Another example presents the usefulness of sharp filters for generating subpixel and intermediate pixel arrays needed to calculate the motion vector. The developed programs are available online at github.com/AHandkiewicz/IIR3D

2025

10.1007/s00034-025-03004-0

https://link.springer.com/article/10.1007/s00034-025-03004-0

CC BY (attribution alone)

open journal

final published version

01.2025

at the time of publication

70