Wikipedia:Main Page history/2014 January 10

From Wikipedia, the free encyclopedia
Welcome to Wikipedia,
4,420,429 articles in English

From today's featured article

Waveguide post filter with tuning screws

A waveguide filter is an electronic filter that is constructed in waveguide technology. Waveguides are hollow metal tubes inside which an electromagnetic wave may be transmitted. Filters are a basic component of electronic engineering designs and have numerous applications. Waveguide filters are most useful in the microwave band of frequencies, where they are a convenient size and have low loss. Examples are found in satellite communications, telephone networks, and television broadcasting. Waveguide filters were developed during World War II for radar and electronic countermeasures, but afterwards soon found civilian applications. Post-war development was concerned with reducing size, first with new analysis techniques that eliminated unnecessary components, then by innovations such as dual-mode cavities and ceramic resonators. Waveguides can support a variety of electromagnetic wave modes: both a disadvantage, spurious modes frequently cause problems, and an advantage; dual-mode designs can be much smaller. The chief advantages of waveguide filters are ability to handle high power and low loss. The chief disadvantages are bulk and cost compared to technologies like microstrip. (Full article...)

Recently featured: John Adair – Prince Albert Victor, Duke of Clarence and Avondale – Cyclone Rewa

Did you know...

From Wikipedia's new and recently improved content:

Ruth A. Parmelee and Armenian children

In the news

Janet Yellen

Recent deaths: Run Run Shaw Eusébio Phil Everly

On this day...

January 10

More anniversaries: January 9 January 10 January 11

It is now January 10, 2014 (UTC) – Reload this page

Today's featured picture

Eastern Phoebe

The Eastern Phoebe (Sayornis phoebe) is a small, migratory passerine bird found in Central and North America. It breeds in woodlands in the eastern United States and often nests on human structures. This specimen was photographed in Madison, Wisconsin, US.

Photo: John Benson

Other areas of Wikipedia

  • Community portal – Bulletin board, projects, resources and activities covering a wide range of Wikipedia areas.
  • Help desk – Ask questions about using Wikipedia.
  • Local embassy – For Wikipedia-related communication in languages other than English.
  • Reference desk – Serving as virtual librarians, Wikipedia volunteers tackle your questions on a wide range of subjects.
  • Site news – Announcements, updates, articles and press releases on Wikipedia and the Wikimedia Foundation.
  • Village pump – For discussions about Wikipedia itself, including areas for technical issues and policies.

Wikipedia's sister projects

Wikipedia is hosted by the Wikimedia Foundation, a non-profit organization that also hosts a range of other projects: