As I see it there are three main areas to consider, its origins and history when referring to antennas, its definition, and its current uses.
The origins of the term are not in doubt. Any number of ARRL and Antenna Engineering books that date to the 40's and 50's and before have excellent descriptions of what a counterpoise was at the time. While all of them are somewhat different from each other, all of them (that I have access to) explain it as a network of wires that are elevated above and isolated from the earth. This allows it to act as one plate of a capacitor with the earth below it acting as the other plate. Most sources call it a capacitive ground, generally referring to a counterpoise by using the paraphrase "sometimes called a counterpoise". Another item of note is the very similar spiderweb diagrams shown for examples of the layout of the ground system. If anyone needs sources for this I am happy to quote several. I would also like to point out that several current sources also refer to a counterpoise in this way, including
this wikipedia article, the current version of the ARRL Antenna Book, and the US Marine Corpse Field Antenna Handbook.
The definition of the word would be the next factor that I examine. We should decide if this definition is even relevant for Antenna Engineering as it does not fit the historical uses of the term, and originates elsewhere in engineering. In mechanical engineering, where the word originates, the term means to oppose a force with an equal and opposite force. Some sources use the term "balancing" force. Looking up multiple different web sources for the definition I get the impression (and some specifically state) that the force must be perfectly balanced, or exactly equal to the force being opposed. I can see several areas where this could apply to antennas.
Finally, its current uses are wide and varied. You can talk to any number of people about this and get just as many answers. Some are very similar, but the details tell the story. This holds true even for those knowledgeable in the field. No two peoples version of what a counterpoise is seems to exactly match any one else. Further, the best reason I seem to be able to get is "because xxx used it that way and they know what they are talking about". These people referred to are presented as well known in the field, and typically I have never heard of them. I put most responses in three categories:
1) The radial system on an antenna. For some people it must be elevated, some people include buried radials. Some people include radials that are angled down while others don't, ect. This is by far the most common group.
2) Anything connected to the shield connection on the coax. This would be the second most seen definition.
3) Everything else. This includes whatever doesn't fit the two above. For example, the video below where wires are buried in the ground underneath a horizontal antenna and attached to a coax somewhere up the feed line from the antenna is referred to as a counterpoise.
Ham Radio MARS Counter Poise Ground Saturn Dipole Antenna - YouTube
I typically can generally figure out what someone is talking about via the context of how the term is used, however, if you have one definition in your head and hear/see the term used in a another way that bears no resemblance to your own definition you may be confused. The confusion is compounded for those who are new and are simply trying to learn.
One observation I have made about all of the uses of the term "counterpoise" is that there is no use of the word that doesn't already have a more accurate and descriptive word/phrase already in use to describe what is being referred to.
The above are simply my thought processes. None of it is written in stone. Some categories may be more relevant than others to some people and less relevant to others.
I, personally, am in the traditional definition camp, After all, that is where the term when used with antennas came from. Many newer publications are now including (and others are going back to aka ARRL Antenna Books) it as their definition as well so it seems to be making a comeback.
I'm not sure about the definition that is often given as it originates in mechanical engineering. Antenna theory is part of electrical engineering. While they are both fields of engineering I am at a state of a tossup of weather the definition should still apply or be dismissed. Most people see the definition being completely contradictory to the traditional use of the term in the antenna engineering field.
Current uses I want to completely dismiss out of hand, but I don't find myself doing that. Getting X different descriptions from X different people makes me wonder who is in fact correct, if anyone really is at all. That being said, the majority of descriptions out there have similar points. These points, while not fitting in with the traditional definition of the word as it relates to antenna engineering, are non the less a common ground, and that is potentially the start of a new meaning for the word.
Thoughts?
Notes for completeness: There are five separate areas in the ARRL Antenna Book 22'nd Edition that I referred to above where the term "counterpoise" is used. If you use the index to look up "counterpoise" it will give you a page number to a page that has two sentences, a diagram, and a one or two sentence caption to the diagram and that is it. Looking through the book one day I found information in Chapter 9 that contained several paragraphs, another diagram, another caption, and a reference to more information in Chapter 3. In chapter 3 there is a whole subsection with more diagrams. Nothing in chapters 3 or 9 is listed in the index of the book, yet, they contain one of the most complete descriptions I have seen anywhere what a counterpoise is.
Two other areas in the book the term is used as part of the phrase "acts like a counterpoise". I put forth that the context is the differentiator in these cases, as acting like something is not the same as being something.
The DB
