Harry36

omni800-2600.cst

https://iopscience.iop.org/article/10.1088/1367-2630/14/3/033001

3. 4

I figured out what's wrong When the reflector was added to my project, it was not coaxial to the stern and the offset angle was not observed. Because of this, the deviation on the first port is almost zero.

Due to the deviation of the phase center of the antenna from the focus of the mirror, the direct direction of the beam from the mirror deviated. All 4 beams will eventually be directed in different directions. It's not good at all. it is not intended for feed.

original - https://ypylypenko.livejournal.com/35552.html boom 20*20 mm dipol dia=8 mm directors and reflectors dia=6 mm cst2021 YUBeta19.cst

1. What is the frequency range? 2. What amplification is needed or what are the overall dimensions? 3. What will the directors and dipole be made of? exact dimensions are required. 4. What will the antenna traverse be made of? 5. what is the method of attaching the directors and the dipole to the traverse. preferably a design sketch or photo examples. Until all these questions are answered, I'm not going to waste my time. I do not see in any topic from you a specific task. Just something to remove or add. Nobody will consider such an option, it takes a lot of time for development and fine-tuning.

50Ω Direct Feed from AMagus (2014 and old version) uda_yagi_folded_dipole_TV_magus_2014.06_td.cst

3D Printed Uda-Yagi ))) http://www.mwelectronics.ru/2018/Papers/058-062.pdf

The antenna is very good. The classic SWR graph of the Uda-Yaga antennas looks like a double letter W. The first W is visible on the screen and the beginning of the second, as it seems to me. That is why I try to show the gain graph, and do not pay attention to the impedance in the figures. Impedance is important to the developer for tuning the antenna, and in the first approximation, the initial SWR and gain are important. If the gain in the range does not start to fall, then the antenna still has a margin up in frequency. I think you need to increase the dimensions a little and you get a great antenna.

300 Ohm bt1727.cst

Good job! If you are modeling an antenna for a narrow frequency range, it is not entirely correct to specify a wide range for the calculation. +/- 100 MHz from the borders is enough. This increases the accuracy of the calculation. As Сlanon said earlier, the antenna is symmetrical and requires a balun (matching - balancing device) to be connected with a coaxial cable. If you simply connect the cable to the points of the discrete port, most likely the calculations and measurements will not match. This is due to the fact that the conductor in the discrete port has a zero diameter, and the real central conductor of the cable by 15 mm will introduce a large inductance, which was not included in the calculation. In simulations, it is best to completely draw the power node to avoid large discrepancies between measurements and simulations. The dielectric constant of wood is approximately equal to 2...3. it is also not included in the model. I think all this will affect the result. results in FD differ by 100MHz... results in FD differ by 100MHz... In fact, this antenna perfectly covers the entire 1700-2700 range with a gain from 12.5 to 15.5. Dimensions should not exceed 250x150mm. If you display the SWR and gain graph, you will understand what I am talking about.

batwing? 350*350 mm reflector?

It seems to me that I saw and read it somewhere? ... ,,,or modeled and wrote a description for this))))

For the TV range 470-790 MHz, the mirror diameter of 0,98 meter is small. You won't get good gain from such an antenna. The maximum theoretical gain at 470 MHz for a dish diameter of 98 cm is 10.6 dBi. for a frequency of 790 MHz - 15.2 dBi. You will get exactly the same parameters using the Uda-Yaga antenna, about 1.2 meters long and about 30 cm wide. https://ypylypenko.livejournal.com/91602.html For manufacturing, you will need an aluminum strip with a section of 15x2 mm, a profile pipe with a section of 15x15 mm, rivets or self-tapping screws, metal cutters and about 1 ... 2 hours of free time. It would be very good to purchase a matching board and a box for it. But if this is not the case, a loop of impedance matching cable will do.The CM4251 antenna is very good and beautiful, it does not need to be dismantled or destroyed. Sell it to antique lovers.

4x4 UNORIGINAL dimensions!

I don't have this antenna. I can only roughly predict the dimensions. Above, I laid out the estimated modeling, but it seemed to you not interesting. I adjusted the dimensions to good results at 75 ohms. I drew a 50 Ohm model in the original design. And played around with the size a bit. There is a reserve for tuning. I think I can get results like the 75 ohm option or better.

))) Antex

Antex 4x4

Setting the boundaries of the output on the charts.