Automated filter design package offers intuitive, graphical approach

February 12, 2016 // By Graham Prophet
Advanced Solutions Nederland has formally released version 3.0 of its ASN Digital Filter Designer. The company says that the package, for IIR and FIR filter design, offers an intuitive route to implementing digital filters that represents the first significant advance in this class of tools for many years.

The tool is a Windows-based package that assists with design of filters, primarily for implementation on processor targets, but also supporting floating point desktop algorithm development: work in this space has focussed on biomedical applications.

ASN contends that, although existing design tools in the market can produce good results, their roots often date back some way (decades, in some cases), they were conceived for use by an “expert” level of filter designer and considerable specialist expertise is needed to reach those results.

ASN Digital Filter Designer has been structured to use an intuitive input approach that largely dispenses with entering parameters in text fields. Rather, it uses a GUI-based methodology in which the user draws the desired filter response (for classical filter configurations). For those classic designs, the tool will work directly from a graphical input to establish the necessary technical specifications for both IIR and FIR filters. Alternatively, the user can create customised designs by entering specifications as simple symbolic mathematical expressions and then interactively experimenting with settings. The symbolic math scripting language allows exploration of complex designs.

The software supports detailed time and frequency domain analysis and a pole/zero editor to fine-tune a design. Outputs include full documentation and reports, and filter coefficients can be exported other environments (Matlab, etc.) for further analysis or development.

IIR filter design can proceed with classical forms in lowpass, highpass, bandpass and bandstop configurations in Butterworth, Chebyshev Type I, Chebyshev Type II or Elliptic types, with filter orders of up to 100 (in the ‘professional’ version of the tool) supported.


FIR (finite impulse response) filter design is implemented via the Parks-McClellan algorithm, and allows for the design of lowpass, highpass, bandpass, bandstop, multiband, Hilbert transformer, and differentiator filters with orders up to 500.

As an example of the ease-of-use of the package, ASN cites a workshop at the University of Twente (Netherlands) in October 2015 (using the prior version of the tool released in July 2015). 80 undergraduate students from the MIRA research centre for Biomedical Technology and Technical Medicine attended a seminar on digital filter design with the ASN filter designer. The day comprised of a seminar and hands-on session with the software tool, as part of a ten week final project.

According to ASN’s CEO, Dr. Sanjeev Sarpal, the students were able to make immediate and effective use of the tool, “We were very enthused by the response from the students, and its appropriateness within an educational environment despite it being commercial product which for the first time speeds time to market for new product development.“ Dr. Ir. Bert-Jan van Beijnum, Assistant professor, University of Twente, remarked on the, “...student involvement [with] an innovative product, that is set to advance the development of biomedical signal analysis and filter design.”

A download is here, and demonstration video here. A demonstration licence (see next page) is free; the “educational” level is €199; and the “professional” version is €699.

Advanced Solutions Nederland;

Next page; key feature list, product options.