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Dr. Pepper

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About Dr. Pepper

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  1. Updated version of the Biquad in a pot for 2.4 GHz, this time with a better impedance match over a wider frequency range and vswr starting at 1 ;-). But as mentioned before there are better designs out there. Parameters
  2. This is indeed much simpler and more stable over a wide frequency range. The idea with the directors is also not bad, perhaps with this the reflector can be a little bit smaller.
  3. You are right, its not perfect. But the first goal was reach 16 dBi. I will try to tune the design for a more stable range.
  4. Biquat + Horn for 2.4 - 2.5 GHz & optimized for gain Size Impedance + Gain Parameters: File: Biquad 2-4ghz-double-reflector.cst
  5. And another variant of Batwing antenna, this time optimized for maximal gain and only one small frequency region (2.4G Wifi). With this restriction you can realize 13dB gain with this antenna. So the Batwing design is very flexible, can be brought band, small band, dual band, 3D printed, gives high gain and is relative easy to manufacture. Gain: S11 + VSWR: Impedance: Dimensions: batwing max gain-endcalc.cst
  6. It would be nice to have a small database about all cst files which can be found here or in other forums like lan23 etc. I found a nice github page with a few designs. With this its easier to adapt an antenna to a desired frequency or if you want to make one to simply catch the measurements from the file. https://github.com/rookiepeng/antenna-models
  7. Additional a scan over a wider freq range to look how broadband the antenna is, and yes its very broadband. Usable from 4.15 GHz to 6.8 GHz:
  8. I have recalculated Admins 5 Ghz batwing (Page 8) for better SWR if somebody want to make one. I also found that the SWR could be improved if the leg is not touching the reflector, so i added a hole at this place to reduce contact which seems to work. From the calculations the antenna should perform and work very well: Gain: VSWR + S11: Dimensions (this thing is tiny ): Impedance:
  9. I played around combining batwings together, look what happen when you combine 3 batwings, easy 15.5 dBi (only calculated to fit 2.44 GHz but can be also very broadband): Also interesting when you combine this bad boy with a second one into an 2 X 1 array (18 dBi): Impedance and size: When 15dbi is also ok the size of the reflector can be smaller. To squeeze out the last bit of gain cst calculated a bigger reflector. It is still calculated without any support to hold it up but i think the design has potential ;-).
  10. Update about the 3D Batwing. I had to optimize the reflector also. Now the antenna gives also proper gain in the 5.2 GHz range as in the 2.4 GHz range. Attached the new dimensions and Results. Please keep in mind, this only works when 3d printed. A bare metal antenna will have other dimensions! Dimensions: Gain: SWR + Impedance: Dual Band Batwing.stl
  11. If somebody is interested in this you can find a model on thingiverse but its important how you attach this yagi on the router antenna. It influences the swr strongly. I found it works best at the start or end of the antenna like in the pictures and worst in the middle. Best is to try some positions from top to down and look on the signal strength on the receiving end.
  12. A new experiment with a 3d printed batwing + Copper tape. This time with a carefully optimized design for good swr. Ive got a very good swr right on the spot without any adjustment of the antenna and the signal strengt of a 5ghz signal improves also a lot compared to a rubber duck antenna (~50% to ~70%). Unfortunately the gain drops a little with this design but at least it works good enough. This is the compromise you have to go when trying to use a dual band antenna. The RG316 is about 20cm long, so the measured swr shows a little to low values, but somehow you have to bring the signal to the antenna . Attached some information about the design. Measured SWR of 1.02 and picture: Dimensions: Wave plots for 2.4 and 5.2 GHz: Gain over Frequency plot: SWR Curve + Impedance plot: batwing dual band-3d-2.cst dual band batwing.stl
  13. I also thought about such a design like a fractal antenna to increase bandwidth and perhaps gain but i don't know if you can reduce the distance so much that two batwings are touching. I found a paper about stacked batwings but this is a little different. stacked butwing.pdf
  14. Sounds like a plan, but give me some time to better understand what im doing ;-) i use the program for one day right now.
  15. I use a relative new laptop called Legion 5 with i7-10750H (6 cores, 12 threads) and an RTX-2060 as graphics card. Would be nice to use more of the cpu power. When cst runs on cpu mode for some tasks it only uses ~40% of the cpu but when it uses the gpu the cuda cores are used to about 90%, then this task is done very fast. When only the cpu is used it takes some time for calculation. Most of the time the Laptop is in idle mode, it can use its power to calculate new dimensions in this time. But i already reduced the parameters of interest to the reasonable ones (max. 3-4) and i also reduce the max. number of evaluations to 20-100 and also the domain accuracy to 0.5 to speed things up when running the optimization. Later on i test again with a higher accuracy and more evaluations but the result didn't change that much.