Developer: MTK-Digital

Current Version: 1.3

Last Updated: 1 year ago

Download Size: 2.5 MB - Download


FilterDesignLab-IIR is a design and simulation environment for digital Infinite Impulse Response (IIR) filters. It is structured into four views for designing the gain, analyzing the phase, simulating test signals, and generating code and filter coefficients.
For a given filter brickwall specification of a digital lowpass, highpass, bandpass, or bandstop, it instantaneously finds the optimal Butterworth, Cheby-I, Cheby-II, or Elliptical filter of lowest order. The phase shift, the group delay and phase delay and the location of the poles and zeros of the transfer function are displayed along with the filter gain. The design and simulation occurs in real-time and is done either by mouse or text input.

The resulting digital filter is instantaneously applied to a test-signal or an imported data set (csv, ascii, txt - format). The test signal resembles either a shifted noisy sine wave, or a step, respectively, delta impulse signal. The raw and the filtered signal are displayed either in the time or in the frequency domain (i.e spectral analysis).

The resulting filter algorithm can be realized in a normal form or a second order structure in the direct form 1 or direct form 2. The numerical stability of the resulting algorithm is calculated for a DOUBLE-precision implementation. The filter function can be generated for signal postprocessing or for real time applications, where new data is entering the system at a given rate.

The resulting filter coefficients of the corresponding recursive time domain algorithm are available for further use and accessible by Copy&Paste. Alternatively, the code of a double precision Matlab®-Function, or C-function is provided and can be exported into a file.

The user can save individual filter designs. The different plots can be exported into PDFs. Each plot features zoom functionality to visually focus on relevant areas and allow for precision editing.


Release Notes:

Support for mac OS Sierra


Most Helpful Reviews

Version 1.1
Review by gcalvarez

Powerful app. A lot of bang for the buck. - I have found this to be a very useful app, though maybe not for what the developer intended! As an amateur radio operator, this is a wonder piece of code as a educational tool. It allows for the visualization of common filter types (bandpass, lowpass, high pass, for example) that every amateur should be familiar with in operational use. The app allows the user to play with various realizations of each filter type and to see the strengths and limitations of the various functions used to generate them. I like that the filter coefficients are easy to access and export in various forms. I also like that the developer made it easy to export PDFs of my filter designs (though an improvement would be offer more than just PDF as an export format, so as to make it easier to put the filter panels into say a powerpoint presentation). It is a well thought out app.

Found helpful by 1 out of 1 people