eco32

To know what to do ot not to do, It is not always possible to buy what you want. RND and learning

bacfire VS dish 1296MHz similar diameters, after long optimalisation in Matlab (end usage of thos tool soooooon)

may I ask, why 75 ohms, surely less copper in the transmission line and cheaper cost. Russian military antennas not knowing why, are all 75ohm?

Biloop by ua9yed in HFSS tool, almost 11dBi from https://www.lan23.ru/forum/node/885/page11 Here calculated on HFSS-11, the sizes took the same as you, only rings of copper cross-section 2.5 mm and the distance to the reflector 12 mm! In principle, and the results of the calculation are the same.I'll try to mess with coaxial feeding ..see what happens:mda: It turns out not big distortions of symmetry.Actually so it should be at such power supply.

I have no more excuses

I've had CST installed for over a year, just haven't had time to switch. How to get started? Colleagues, if you can help me get started, it will be full of benefit for everyone's in the community.

47cm

I can only use dipole with reflector with out circle and without ring in Matlab, i got 15,4dBi on this moment and optymalisation is in progress, Radius 47cm Heightt 21cm Spacing ~50cm freq 1296MHz

This ring works as a director or as a fresnel ring (assuming that this cross dipole is normally located in the cavity chamber)?

thats the andrew mcneil style: It is worth seeing what is inside, how it is made, while its conclusions and interpretations must be approached with great distance

What about dieletric as a microwave lens? It's probably the only chance to get more than 17dBi.

my observation from Backfire Antenna with dipole is more efficient than grid 900mmx600mm with dipole for 1296Mhz has 17.3dBi, smaller bacfire with diameter 57cm has also 17dBi and can be increased by adding fresnel ring to 22dBi (20 .... 21.05dBi in simulation). exemple how it may look like: (Yes, it is a dipole with coaxial splited balun and cavity)

@Admin "From R-409, on a common reflector two antennas, one larger 120-240 MHz gain 9 dB, four smaller 240-480 MHz gain 13 dB." "Two-element in-phase antenna array, zigzag emitters with a reflector (DB-11). Frequencies 120-240 and 390-429.8. Stood on R-415, R-419. Army VHF antenna DB-12 from the R-415 radio kit. Represents a broadband dipole. Dipole arms are 20 cm. Operating frequencies from 390 to 430 MHz."

It exist in R-415, R-419 manual, it is out of the google searchnig, i did not check Yandex.ru yet. It exist in paper version, some hams from my area has it, it is not eassy to get. It may comes from Radio Factory Omsk

"Two-element in-phase antenna array, zigzag radiators with a reflector (DB-11). Frequencies 120-240 and 390-429.8. Were on the R-415, R-419. Army VHF antenna DB-12 from the R-415 radio set. It is a broadband dipole. The dipole arms are 20 cm each. Operating frequencies from 390 to 430 MHz." VHF 120-20MHz in VHF 9dBi UHF 390-429.8Mhz in UHF 13dBi Gain of those version with grid is unknown