BIOPAC® Systems, Inc. Logo

Band-pass and band-stop filters

A band pass filter allows the energy concentrated between two given frequencies (X and Y) to pass while it attenuates the signal's energy at other frequencies. It is equivalent to applying a high-pass filter at X and a low pass filter at Y.

A band stop filter attenuates the energy in the frequencies between two given frequencies (X and Y). It is equivalent to applying a low pass

filter at X and a high pass filter at Y.

 

Note that filters do not remove all of the energy outside of their pass band (the pass band is the frequencies between X and Y for a band pass filter, and below X and above Y for a band stop filter).  Generally, the further away from the cut off frequencies (X and Y), the greater the attenuation of the energy.  How fast the attenuation increases as a function of frequency is established by parameters (primarily “Q”) of the filter.  Real filters will also attenuate within the pass band, and there are some tradeoffs in the selection of parameters.

 

Page last modified 23Dec2014

Associated Applications

Associated Disciplines

Spotlight On
wireless NIRS imager

fNIR Mobile Imaging Systems

High-performance mobile fNIR Imaging Systems are stand-alone functional brain imaging solutions for continuous NIR spectroscopy (NIRS). These top of the line systems provide cognitive function assessment and eliminate a great many of the drawbacks of a functional MRI. Mobile subjects are comfortable and can respond naturally in real-world situations to take a test or perform mobile […]

View All
Latest News

New Citations | Twinkle, Twinkle, Little Star, Muscles & Computer Mice

Recent Studies using BIOPACs MP-Series (MP160, MP150) data recorders, ECG Amplifiers, and BioNomadix Wireless recorders: Singing style to infants Mothers around the world sing to infants, presumably to regulate their mood and arousal. Lullabies and playsongs differ stylistically and have distinctive goals. Mothers sing lullabies to soothe and calm infants, and playsongs to engage and […]

Neuromarketing Interview | How VR Can Improve Marketing Research

Alex Dimov, BIOPAC Sales Executive, was interviewed at the Neuromarketing World Forum by Inside Marketing to discuss how virtual reality can improve marketing research. Alex explains how VR can be used to present virtual iterations of a product to save time and money, and notes that measuring physiological responses adds lots of information for product and messaging […]

Read All
Request a Demonstration
Request a Demonstration