DSP Blockset

Filter Design, Analysis, and Implementation with the Digital Filter Design Block

The Digital Filter Design block (in the Filter Designs library) is useful for designing a digital FIR or IIR filter from scratch, and then implementing it. (To implement a filter you already designed, see Implementing Predesigned Filters with the Digital Filter Block.)

The Digital Filter Design block is ideal for simulating the numerical behavior of your filter on a single- or double-precision floating-point system, such as a personal computer or DSP chip. The block also generates highly-optimized Real-Time Workshop C code for use in floating-point embedded systems.

Filter Design and Analysis.   You perform all filter design and analysis within the Filter Design and Analysis Tool (FDATool) GUI, which opens when you double-click the Digital Filter Design block. FDATool provides extensive filter design parameters and analysis tools such as pole-zero plots and impulse response plots.

Filter Implementation.   The block automatically realizes the filter you design using the filter structure you specify, so you can use the block to filter signals in your models. You can also change some of the filter specification parameters while the block runs in a simulation, which may be useful for fine-tuning the filter. The outputs of the Digital Filter Design block numerically match the outputs of the filter function in the Filter Design Toolbox and the filter function in the Signal Processing Toolbox.

Saving, Exporting, and Importing Filters.   The Digital Filter Design block allows you to save the filters you design, export filters (to the MATLAB workspace, MAT-files, etc.), and import filters designed elsewhere.

Examples and Related Topics.   See the following examples and documentation to learn how to use the Digital Filter Design block:

• Example: Using the Digital Filter Design Block to Design, Analyze, and Implement a Filter
• Example: Saving, Importing, and Exporting Filters
• Digital Filter Design block online reference page -- Details about the capabilities of the Digital Filter Design block
• The Filter Design and Analysis Tool (FDATool) GUI topic in the Signal Processing Toolbox documentation -- All about the GUI you use to design filters with the Digital Filter Design block.
• Topics Covered in the section about designing and then implementing filters -- List of other DSP Blockset filtering topics related to designing, analyzing, and implementing filters.

Choosing Between Digital Filter Design Block and Filter Realization Wizard

Example: Using the Digital Filter Design Block to Design, Analyze, and Implement a Filter