The Critical, High-Value Functions Of FM-Band High Pass Filter

In the realm of electronics and frequencies, “filters” come in various shapes and sizes, and they play crucial roles too, among which include “attenuating” or isolating/segregating the various signals and frequencies. Among the major filter types include “high pass” filters, which are defined as devices that pass, or allow the entry, of signals with a frequency higher than a certain cut-off frequency. The filter blocks or hinders signals with frequencies lower than the cutoff frequency too. Let’s take a brief yet insightful look at how FM band high filters are constructed, and what roles they perform.

The FM (Frequency Modulation) Band

Of the different frequencies in the radio (or electromagnetic) spectrum, the FM broadcast band is one of the most visible, and the most popular, as it’s used for FM broadcast radio by different stations, although the frequency range differs in different parts of the planet, and it’s in this environment that FM band high pass filters thrive.

In Europe, Australia and Africa (which is called the ITU region 1), the FM band goes from 87.5 to 108.0 megahertz (MHz), which is also a portion of the VHF band. In North and South America (ITU region 2), the FM band ranges from 87.9 to 107.9 MHz, while in Japan the FM broadcast band ranges from 76.0 to 90 MHz.

FM, or frequency modulation radio originated in the United States during the 1930’s, and it was created by a seasoned electrical engineer named Edwin Howard Armstrong.

However, use of the FM band only became prevalent in the 1960’s. FM radio waves can actually be generated at any frequency, and all the bands mentioned earlier are part of the VHF range, or very high frequency, which extends from 30 to 300 MHz.

The Roles Performed By FM Band High Pass Filters

To ensure that the various frequency bands in the FM realm do not overlap, or box each other out, “filters” play the roles of traffic policemen, by either allowing certain signals to pass, and by restricting the entry of others.

In the FM band, high pass filters allows for the easy, unhindered passage or entry of high-frequency signals from source to load, and the difficult passage of low-frequency signals. And depending on their construction (and capacity) FM band high-pass filters either cover a certain range, or they can cover the entire FM spectrum from 87.5 to 108 MHz.

Today, hundreds (if not thousands) of FM stations use band pass filters, which offer fully-adjustable input and output, and provide superior tuning and performance all over the entire VHF FM band. The high pass filters used for the lucrative FM band can also be factory-tuned to specific frequencies, and they’re also re-tunable on whole frequency bands.

Apart from being used by radio stations, the FM broadcast band is also used by many of commercially-available and inexpensive wireless microphones, like the ones you see in karaoke joints, along with wireless headphones, which are tunable to only a subset of the broadcast band.

However, higher-quality wireless headphones make use of infrared transmission, instead of the FM broadcast band, to transmit to UHF frequencies like 315 MHz, 915 MHz or 2.4 GHZ.

FM transmitters are even used for spying or surveillance purposes, so that spies and intelligence operatives can “snoop” on their targets. And in this field, FM band high pass filters reign, and do their jobs smoothly, and efficiently!