Band-pass filter
The main function of such a filter in a transmitter is to limit the bandwidth of the output signal to the band allocated for the transmission.
They are often used in sound pressure level competitions, in which case a bass tone of a specific frequency would be used versus anything musical.
A leading example is the use of bandpass filters to extract the business cycle component in economic time series.
This reveals more clearly the expansions and contractions in economic activity that dominate the lives of the public and the performance of diverse firms, and therefore is of interest to a wide audience of economists and policy-makers, among others.
It is very common for a researcher to directly carry over traditional methods such as the "ideal" filter, which has a perfectly sharp gain function in the frequency domain.
As a poignant and simple case, the use of an "ideal" filter on white noise (which could represent for example stock price changes) creates a false cycle.
An early work, published in the Review of Economics and Statistics in 2003, more effectively handles the kind of data (stochastic rather than deterministic) arising in macroeconomics.
These have been successfully applied in various situations involving business cycle movements in myriad nations in the international economy.
Hussaini et al.(2015) stated that, in the application of wireless communication, radio frequency noise is a major concern.
[4] In the current development of 5G technology, planer band pass filters are used to suppress RF noises and removing unwanted signals.
[5] The necessity of adopting asymmetric frequency response is in behalf of reducing the number of resonators, insertion loss, size and cost of circuit production.
Moreover, the stop band rejection and selectivity present a good performance in RF noise suppression.
The band pass filter designed by Shahruz (2005), is an ensemble of cantilever beams,[6] which is called the beam-mass system.
Ensemble of beam-mass systems can be transformed into a band pass filter when appropriate dimensions of beams and masses are chosen.
In neuroscience, visual cortical simple cells were first shown by David Hubel and Torsten Wiesel to have response properties that resemble Gabor filters, which are band-pass.
