Bandpass Filters and Why RC Series Circuits Aren’t Cut For It

Computer and Technology

What are bandpass filters?

A bandpass filter is an electronic circuit or device which allows only signals between specific frequencies to pass through and attenuates or rejects frequencies outside the range. They are mainly utilized in transmitters and receivers that are wireless. Their main function in this kind of bandpass filter application is that they are used to put a limit on the amount of bandwidth. This bandwidth is referred to the output signal. It has to be only at the most minimum bandwidth required including the ideal speed and ideal form.

A bandpass filter also optimizes the signal-to-noise ratio of a receiver. At the same time of transmission and receiving applications, these bandpass filters must have the optimum bandwidth for the form and speed used at the moment. With this, they are able to reach the maximum number of signals being transferred from one system to another.

What are RC series circuits?

A resistor–capacitor circuit or also called an RC circuit is a device wherein the capacitors and resistors are triggered by an electric source. Moreover, they are used to filter out a signal. The most well-known types of RC series circuits are called high-pass filters and low-pass filters.

Why can’t RC Series Circuits be used as Bandpass filters?

Unlike a high-pass and low-pass filter a bandpass filter has two frequencies of interest. This means it requires two storage elements instead of one.

To put it simply:

  • High-pass filters blocks signals below x
  • Low-pass filters blocks signals above y
  • Band-pass filters block signals below x and those above y

An RC series circuit exhibits high impendence to signals of low frequency only hence it can be used to represent a low pass filter, but as a band pass filter it will fail.