Harry36

version? 22 or 23?

https://www.3ds.com/products-services/simulia/products/cst-studio-suite/latest-release/

DS SIMULIA CST STUDIO SUITE 2023.01 SP1 x64

https://ieeexplore.ieee.org/document/1282144

Figure 2 in the quote shows the dimensions of the antenna for LTE800 band (min swr~ 850 MHz), it is made in the form of two antenna sheets on different sides of FR4. the dimensions match the simulation quite well. In order to make a similar antenna for a frequency of 1296 MHz, you need to reduce the dimensions by a factor of 1.52 dimensions. The antenna has a fairly low gain of ~7.2 dBi. This is due to the minimum size of the reflector. By increasing the reflector to 250x250 mm, you can increase the antenna gain to 9.5 dBi at the same time, if you do not change other dimensions, the SWR also increases to a value of 1.1. tFR4=1mm, tCopper=0.018, H=28.4. Antenna connection is shown in fig. 1 quota is performed without balancing, this is a wrong connection. The cable must be soldered from the side of the web of one of the antennas (upper or lower) and brought along the arc of a circle to the middle of the frame (circle), then lowered onto the reflector, where to install the connector. Cable use RG-316. FR4 is a rather unstable material and antennas made from it very often fall outside the calculated range. for home production without appliances, it is not entirely suitable. it may be easier to make an antenna out of metal. For example, by type BDM. reflector and two disks. this will give a fairly wide bandwidth at a very low SWR and will forgive manufacturing errors even with a hand tool. or stack 2x2 or dipole from metal can dia=66.3 mm

It's not dipole, this is biguad + balun )

Try to draw a balancing device in the model.

This is 50 Ohm version.

edge feed - 2mm height 2.4 mm nut m3 (h =2.4) nylon 2 pcs screw m3 (l =10 mm) nylon from edge 4 mm vvibrator_1.1.cst

Sputnik_V1727.cst

what do you think about the losses of copper and galvanized steel? 0.01 dBi?

I don't get the specs for that size.

LiteVNA costs about $80 for the 2.8-inch version. https://aliexpress.ru/item/1005003802185241.html?spm=a2g2w.productlist.0.0.616ed52d8qmiOH&sku_id=12000027216067991 and about $100 for the 4" version https://aliexpress.ru/item/1005004126788962.html?spm=a2g2w.productlist.0.0.616ed52d8qmiOH&sku_id=12000028123208491 The prices for these devices are very affordable and they work quite accurately.

https://ypylypenko.livejournal.com/101234.html

Structural aluminum dipoles are very expensive to make at home, and can be made even easier with galvanized steel.

IMHO for lte1700-2700 very nice

38*38*6 mm steel

make directors from a core of a copper cable for electrical wiring (see the typical diameter from the wire section). The directors holder can be made from a thin strip cut from galvanized steel, like the butwing itself, the directors can be soldered onto the holder simply and quickly. you can fix the holder to the "batwing" racks with rivets. and I would slightly increase the size of the antenna so that the maximum gain falls on the desired frequency (2.45) or to capture the entire band 1700-2700 in SW<2...1.5. the size of the antenna (more precisely, the reflector) will directly determine the gain

great job! there's still some tuning left in the region of 2 GHz there is a break in the SWR graph. change the dimensions of the directors (diameter and height above the batwing, it is not necessary to do everything at the same height) and you should get a broadband antenna like I have on Lan23 Making a narrowband antenna is not so difficult, but stretching the bandwidth to the maximum is much more interesting

You don't have sidelobes on the x-axis and quite large on the y-axis. Try resizing the reflector ;-) , this should help flatten the radiation pattern and raise the gain.You don't have X-axis sidelobes and quite large Y-axis ones. Try resizing the reflector ;-) , this should help flatten the radiation pattern and raise the gain (energy from the sidelobes will go into the main direction). The antenna is symmetrical and requires a Balun to connect the coaxial cable. It seems to me that this has nothing to do with the loop antenna (Kharchenko's bi-square), this one can be considered as a broadband dipole with a shunt or as a slot. One of the simplest options for a balun is to lay a cable along the slot to the zero potential point (connecting the two halves of the emitter sheet) and leading it to the side of the reflector. But this option requires a relatively small diameter cable, preferably with a TEFLON dielectric and an SMA flange crimped on it. Not everyone has such a cable. it seemed to me that at home it is easier to make the balun suggested by me on the previous page. You can multiply the dimensions in the project by 2.5 - 3 and get the dimensions for the range 1.7-2.7 If you adjust the dimensions, then the structure fits into the perimeter of a metal can with a diameter of 99 mm. This is a very simple and quick solution for home-made from scrap materials.