N78 Antenna

[Alumni 0]

On 3/20/2025 at 0:43 PM, papagayor said:

Thanks, I've seen this construction, looking for a way to reduce frequency to 3300-3800MHz. Ca it be modified? I want to attach it on a 60cm parabolic disk.

To shift the operating frequency upwards, you'll need to scale down the entire antenna geometry proportionally, since resonant frequency is inversely related to physical size. For your band:

The center frequency shifts from ~2.2 GHz to ~3.55 GHz, which is ~1.6x higher.

So, reduce all dimensions by a factor of ~1/1.6 ≈ 0.625.

Your material choices (copper sheets/tubes or aluminum with proper mounting) are reasonable. Soldering for copper is perfect; for aluminum, ensure electrical continuity between parts, self-tapping screws or conductive paste with bolts can work

[papagayor 3]

Without simulating the antenna is difficult for me, because as I've seen by seeking online, when an element size change the whole antenna elements must be change, because not only elements size is critical but also distance and position on reflector is critical too. I liked the Kathrein antennas procedure as they are very simple, and trying to make something similar by 4 copper sheet dipoles soldered on copper tubes and then solder tubes on reflector. Also I saw somewhere a Kathrein dipole antenna, that was like an upside down Π, that was a simple idea but cannot make the calculations.

All I need is to make and mount a 3300-3800MHz antenna on a parabolic dish

Edited 21 hours ago by papagayor

[Admin 2638]

papagayor...see this 

",,,such an antenna can be calculated for the 3300-3800 MHz band"

[papagayor 3]

Calculations are not my best, so asking ChatGPT and DeepSeek for help by giving some dimensions and ask them to calculate frequency, or opposite, until I find a simple but good solution

[Admin 2638]

ChatGPT  or DeepSeek will never be able to solve your problems in a real way...it's fake"

[papagayor 3]

Then I have no luck, only by continue seeking online for some plans

 

[Admin 2638]

I think I'll make you a good antenna for the desired frequency."

[papagayor 3]

Thank you very much sir, but please can't my drawings be modified to work in this area? Because they're easy to be made for my skills. Also a dual polarized batwing with two ports would interesting.

[papagayor 3]

Or like this one

[papagayor 3]

Also I made a dual biquad, based on online calculations, and even I cannot test it for performance, my speedtests increased very much, i was taking -test in the morning when no much clients in ISP antenna- 30-50 Mbps and now it go up to 60-80 and some times over 150. I can't understand too much about measures, but looking in router results I took the attached measures, the SINR is not always the same it goes up-down to 1-10/

DBQuad.pdf

Edited 5 hours ago by papagayor

[Admin 2638]

1 hour ago, papagayor said:

Or like this one

I will design you such an antenna for the desired frequency....!!!

[Admin 2638]

,,,this is for you...(Why isn't you forget to see about Messages(up)

 

3300-3800 MHz BESTER.cst