Talk:Ground plane

Latest comment: 1 month ago by MarkMLl in topic Receiving antenna

Dictionary

edit

This seems like more of a dictionary defintion than an encyclopedia article. I think it should go on Wiktionary instead? (See Wikipedia:What Wikipedia is not. Axlrosen 19:02, 18 Oct 2003 (UTC)

Receiving antenna

edit

What about the significance of a ground plane for RECEIVING antennas?Jackborn (talk) 21:16, 28 April 2014 (UTC)Reply

I would imagine that the ground plane is not so important for receiving. It might block signals from directly below, if there were any, and if there were they would probably be unwanted anyway. The ground plane is probably more important to ensure the antenna as a whole (including the ground plane) is balanced and has a net zero voltage with respect to its surroundings, and so avoiding any capacitive coupling which would divert the transmitted power to unwanted side-effects. 2001:8003:DD6B:7001:DDCC:7389:4617:DDC3 (talk) 00:17, 9 June 2020 (UTC)Reply

PCB... A power plane is often used in addition to a ground plane in a multilayer circuit board, to distribute DC power to the active devices. The two facing areas of copper create a large parallel plate bypass capacitor which bypass high frequency spikes into ground and prevents noise from being coupled from one circuit to another through the power supply. — Preceding unsigned comment added by 49.35.225.2 (talk) 20:04, 2 November 2016 (UTC)Reply

A reflective array TV antenna and a phased array in a fighter, consisting of dipoles in front of a ground plane
Due to electromagnetic reciprocity an antenna has the same radiation pattern when receiving as transmitting, so ground planes are equally important in increasing the gain of receiving antennas as in transmitting antennas. In general, a properly placed ground plane doubles the power received by an antenna element, since it receives both the direct radio waves and waves reflected by the plane, so it increases the gain of the antenna by 3 dB. A half-wave dipole has a gain of 2.15 dBi, while a quarter wave monopole, made by replacing one side of the dipole by a perfect ground plane, has a gain of 2.15 + 3 = 5.15 dBi. As you say, the cost of this is that the antenna only receives radio waves from one side. A great many receiving antennas use ground planes: the T antenna used in shortwave listening, the phased array antenna used in military radar, the ground plane whip antenna used for CB radios, the reflective array antenna used for TV antennas, which consists of dipole elements in front of a ground plane (see picture). The article should probably be edited to make this clear. --ChetvornoTALK 03:07, 9 June 2020 (UTC)Reply
I've tried to edit the article to clarify the importance of correct connection after asking about this on StackExchange. I considered something like "To have anything other than a wavelength-specific screening effect..." but I'm really not an expert in this area. MarkMLl (talk) 11:51, 15 September 2024 (UTC)Reply