Most of us, even if we not know theory behind do we have experience that a dipole antenna shorter then lambda/2 is less efficient. The shorter, the less efficient.
That is true for all short dipoles and is so well known that I doubt someone can be serious saying that this is a confused kind of cheating.
A dipole 60 mm long will have almost no efficiency used as a 10 MHz shortwave antenna where lambda/2 is 15 meter.
Same antenna may have excellent efficiency at 2.4 GHz as antenna length now is lamda/2.
Somewhere in between do we have 800 MHz, how can that be confusing in a grade that assumtion must be that surounding world is cheating?
A single wire, even if wired around a ceramic core have no dedicated efficiency, that is just silliness.
A single wire is not an antenna, it is as best only a half antenna as groundplane is the other element in a dipole.
Assuming an efficiency for just groundplane is at same level of thinking.
Two of hundreds of links that all says same thing about short dipoles:
Warren L. Stutzman och Gary A. Thiele, heavier antenna names are hard to find among now living (except Vfone then).
In their book
"Antenna Theory and Design" is a short dipole described as very frequency depending in its resulting efficiency:
Always a source of easy to understand information:
https://www.antenna-theory.com/basics/efficiency.php
Above links are not false, lacks knowledge and contains no "adjusted theory" and is not stating some kind of cheating as Vfone assumes.
Others are lacking an unknown kind of KNOWLEDGE which Vfone suppose he have.
This is a kind of statements that often characterizes flat-earthers and crystal healers using unknown forces to create miracles of a kind not known by deadly people.
I thought Vfone was honestly interested in my VNA measurements at 868 MHz why add did completing measurements. It is from technical view nothing new, since long accepted knowledge.
The new part is that my software is able to read directly from a VNA and sort needed data to make process of measuring efficiency very simple compare to previous methods.
Software is solving several else a bit complicated problems.
As an example, Wheelers Cap method says that antenna resistance should be measured at antenna resonance as it then is no reactive losses that interferes. It should be measured with and without a cap. Cap size should be very nearfield covering antenna, less then lambda/2 distance from antenna if possible.
Almost all antennas do however drop heavily in resonance frequency when covered by a small cap and either reading result at VNA at same frequency with/without cap or try to combine result from two frequencies will not result in correct reading.
The more narrow antenna, the bigger will resulting error become. However by using time-domain can this be solved as antenna not is moving around along cable with or without cap.
It is nothing new that this is possible math, but it is nothing that is done with aid of a mini-calculator. A PC software that is doing all heavy calculations is then very practical but for different reasons have nobody but all else known pieces together until now.
Software is since several years evaluated and compared with other measurement methods and is confirmed to be well working and very precise.
It is the first software that included matching losses (15 years ago) in optimizing calculation and the only software that can calculate optimized network of any topology in real time with data read from VNA.
It is the first software that adds auto port forwarding to VNA functions. It was added 7 years ago. It is else a function that is coming at more expensive VNA's today. With AnTune and a 20 years old HP8710 will get it as well.
It was the first software that at all provided a live VNA interface. What live is is depending on VNA and PC but PC screen refresh at least 10-20 times/sec is possible.
Live part is for many hard to understand importance of but when tuning matching networks or antenna shapes can it be compared with tuning coils in an old radio, tuning by turning a coil core and get result 1 second later is 1 second too late.
It is a bit similar situation when old analog voltmeters are preferred instead of a digital multi-meter when doing this kind of jobs.
Tuning network software is relative simple if tuning just for one frequency. This software first version was developed to make it possible to do wide band optimized networks.
It had not been a real need until I had to design the first embedded cellphone antenna and its matching network,
Ericsson A238SC, Ericsson's first embedded antenna. As it was a two-band antenna where both bands needed to be matched must antenna impedance and network impedance completing each other. It can be hard to see at Smith chart in a VNA which antenna impedance that is a ideal to fit with an so far unbuilt matching network with unknown topology so a computer that instantly compared all possible variation was then a must to achieve good result, and still is.
I was back then employed at
Intenna.
Software have since improved a lot but also is today's cell phone antennas demanding in new ways and needs much more then two relative narrow cellphone bands, GSM900/1800 or GSM850/1900.
Adding antenna isolation as a tuneable parameter is one new option that I hope AnTune will handle in maybe a year, but it also depend a lot on its users, what functions they find most important to add.