| A filter always seems to refer to something that will let one
substance through, but block some other substances. The term as
used in wireless is really not very different. An electronic
filter is one that allows some frequencies
through, but will block others. Of course, its main function would
be to allow through the frequency that you want and need, and then to
block any frequency that might be harmful to the wireless product. Electronic filters are a science all by themselves. While they
follow very exacting math, a bystander might see them as an
approximation. By that I mean that they do not simply let through
the right frequencies untouched and they do not totally block the
unwanted frequencies. Depending on the quality of the filter and
its preciseness, it will attenuate or cut
back on even the important signal that it wishes to let through.
However, it attenuates and cuts back even more severely on the undesired
frequencies even much more. Generally speaking, the further away
that an unwanted frequency is from the desired frequency, the more it
will be attenuated (cut back). A wireless product usually has a
number of electronic filters in it. |
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