Band Pass Filter – The Concierge of Radio Frequencies

Band Pass Filter is an electronic device that permits the frequencies of a selected range to pass while baring other signals at unsolicited/unrequired frequencies from going getting into the receiver set and create disturbances thereby.

The main functions of a band pass filter circuit to pass or amplify certain frequencies and accentuate other frequencies. It restricts the bandwidth of the output signal to the band assigned for transmission.

This functionality of a band pass filter prevents the transmitter from interfering with other wireless stations.

There are four major types of filters 1) The low pass filter 2) The high pass filter 2 the band pass filter and 4) the band stop filter.

Please note that the word “Low” and “High” do not indicate any absolute frequency values, but nonetheless, are relative values of the cut-off frequency.

Further, the band pass filter can be placed in 2 categories-1) Active and 2) Passive, depending upon their responsivity and capability of dealing with high and low frequencies.

Passive band pass filter is most amenable to a frequency range of 100Hz to 300MHz. Hi-tech designs can extend the use of passive filters in the gigahertz range.

Active band pass filters are very effective in dealing with very low frequencies-nearing 0Hz. They can yield a voltage gain, which the passive band filters cannot. Active band pass filters are unsuitable for very-high-frequency applications.

Band pass filter perform a critical role in application like power supplies, audio electronics, and radio communications.

Many filters can be found on the Raditek website.