User Reference:IIRBandpass: Difference between revisions
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==Synopsis== | ==Synopsis== | ||
Design an IIR filter consisting of up to three parts (high-pass, low-pass and notch) and apply it as part of the signal-processing chain. To use it as a bandpass, specify the desired lower end of the band as a high-pass corner, and the desired upper end of the band as a low-pass corner. | |||
The filters are implemented as a Butterworth filters of the specified order. | |||
==Authors== | |||
Jeremy Hill | Jeremy Hill | ||
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Filter order for the notch. The default is 4. A value of 0 disables the notch filter. | Filter order for the notch. The default is 4. A value of 0 disables the notch filter. | ||
===Downsample=== | |||
If ''LowPassCorner'' is set, downsample to a sampling rate of circa 4*''LowPassCorner'' provided that is smaller than the current sampling rate. Downsampling is always is done by an integer factor such that the resulting sampling rate is close to (and larger than) 4*''LowPassCorner''. | |||
The default is 1 (do downsampling). | |||
===Rectification=== | |||
If set to 1, negative values will be replaced with zeros (Half-Wave). If set to 2, negative values will be replaced with their absolute values (Full-Wave). Set to 0 (the default) to disable rectification. Note that rectification is done ''after'' bandpass filtering, so another low pass filter is likely required to obtain an amplitude estimate. | |||
==States== | ==States== | ||
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==See also== | ==See also== | ||
[[User Reference:Filters | [[User Reference:Filters]], [[Contributions:HilbertSignalProcessing]] | ||
[[Category: | [[Category:Filters]][[Category:Signal Processing]] | ||
Latest revision as of 19:35, 16 October 2025
Synopsis
Design an IIR filter consisting of up to three parts (high-pass, low-pass and notch) and apply it as part of the signal-processing chain. To use it as a bandpass, specify the desired lower end of the band as a high-pass corner, and the desired upper end of the band as a low-pass corner.
The filters are implemented as a Butterworth filters of the specified order.
Authors
Jeremy Hill
Parameters
HighPassCorner
High-pass cutoff frequency. The default is 0, which disables the high-pass.
HighPassOrder
Filter order for the high-pass. The default is 2. A value of 0 disables the high-pass.
LowPassCorner
Low-pass cutoff frequency. The default is 0, which disables the low-pass.
LowPassOrder
Filter order for the low-pass. The default is 4. A value of 0 disables the high-pass.
NotchCenter
Notch center frequency. The default is 0, which disables the notch filter.
NotchOrder
Filter order for the notch. The default is 4. A value of 0 disables the notch filter.
Downsample
If LowPassCorner is set, downsample to a sampling rate of circa 4*LowPassCorner provided that is smaller than the current sampling rate. Downsampling is always is done by an integer factor such that the resulting sampling rate is close to (and larger than) 4*LowPassCorner.
The default is 1 (do downsampling).
Rectification
If set to 1, negative values will be replaced with zeros (Half-Wave). If set to 2, negative values will be replaced with their absolute values (Full-Wave). Set to 0 (the default) to disable rectification. Note that rectification is done after bandpass filtering, so another low pass filter is likely required to obtain an amplitude estimate.
States
None.
See also
User Reference:Filters, Contributions:HilbertSignalProcessing