Browse Definitions :
Definition

bandpass filter

A bandpass filter is an electronic device or circuit that allows signals between two specific frequencies to pass, but that discriminates against signals at other frequencies. Some bandpass filters require an external source of power and employ active components such as transistors and integrated circuits; these are known as active bandpass filters. Other bandpass filters use no external source of power and consist only of passive components such as capacitors and inductors; these are called passive bandpass filters.

The illustration is an amplitude-vs-frequency graph, also called a spectral plot, of the characteristic curve of a hypothetical bandpass filter. The cutoff frequencies, f1 and f2, are the frequencies at which the output signal power falls to half of its level at f0, the center frequency of the filter. The value f2 - f1,expressed in hertz (Hz), kilohertz (kHz), megahertz (MHz), or gigahertz (GHz), is called the filter bandwidth. The range of frequencies between f1 and f2is called the filter passband.

Bandpass filters are used primarily in wireless transmitters and receivers. The main function of such a filter in a transmitter is to limit the bandwidth of the output signal to the minimum necessary to convey data at the desired speed and in the desired form. In a receiver, a bandpass filter allows signals within a selected range of frequencies to be heard or decoded, while preventing signals at unwanted frequencies from getting through. A bandpass filter also optimizes thesignal-to-noise ratio (sensitivity) of a receiver.

In both transmitting and receiving applications, well-designed bandpass filters, having the optimum bandwidth for the mode and speed of communication being used,maximize the number of signals that can be transferred in a system, while minimizing the interference or competition among signals.

This was last updated in November 2006
SearchNetworking
SearchSecurity
  • man in the browser (MitB)

    Man in the browser (MitB) is a security attack where the perpetrator installs a Trojan horse on the victim's computer that is ...

  • Patch Tuesday

    Patch Tuesday is the unofficial name of Microsoft's monthly scheduled release of security fixes for the Windows operating system ...

  • parameter tampering

    Parameter tampering is a type of web-based cyber attack in which certain parameters in a URL are changed without a user's ...

SearchCIO
  • chief procurement officer (CPO)

    The chief procurement officer, or CPO, leads an organization's procurement department and oversees the acquisitions of goods and ...

  • Lean Six Sigma

    Lean Six Sigma is a data-driven approach to improving efficiency, customer satisfaction and profits.

  • change management

    Change management is a systematic approach to dealing with the transition or transformation of an organization's goals, processes...

SearchHRSoftware
SearchCustomerExperience
  • clickstream data (clickstream analytics)

    Clickstream data and clickstream analytics are the processes involved in collecting, analyzing and reporting aggregate data about...

  • neuromarketing

    Neuromarketing is the study of how people's brains respond to advertising and other brand-related messages by scientifically ...

  • contextual marketing

    Contextual marketing is an online marketing strategy model in which people are served with targeted advertising based on their ...

Close