eco32

That's what my fellow senior radio amateurs tell to me

I have two same grids, lets fin out how it will be in thi combination (simple ilustration): (simulation without optymalization shows inceasing gain from 17.2dBi to 19.6dBi)

@Admin has right @anoduck: You can use siple laser pointer to findout where your beam is radiating. focus point can be checked by peaper sheet and sun focus point can be checked by peaper sheet and sun. BTW: The sun generates a lot of noise and pointing the anena at the sun You can also adjust the focal point.

I have acces only to "A Novel Wideband Quasi-Yagi Antenna for Base-station Applications", the is no dimensions. From charts it looks like this is antenna for a ~2.3GHz and ~3.3GHz

Is there a director shape that works best, a square, a loop, a simple rectangle , (...)?

In my understanding of MIMO, these antennas transmit separate signals, +45 and -45degr, in the simulation should be considered separately and not together. Gain will be 6dBi, not 9dBi.

Prototyping ongoing

Design with slot or with coaxial splited balun - the reflector disc is smaller than the previous design, I guess that's the reason for the lower gain.

WOW! The antenna is very broadband! It Covers the entire 23cm band, this type of design is also suitable for LTE/5G I have read that for grid parabolic antennas the reflector can be narrower, it does not have to be a circle, it can be a rectangle with rounded corners With my firs 13dBi design, I made the QSO with 250mW over a distance of 8km using the reflection of a tall office building. (I have different grids: 600mmx400mm 13dBi, 700mm x 900mm 17dBi)

MIT Radiation Lab Series V12 Microwave Antenna Theory and Design 1949 chapter 8 Microwave dipole antennas and feeds https://www.scribd.com/document/35903457...and-Design#

This type of antenna is patented : US5191350 LOW WIND LOAD PARABOLIC ANTENNA, for more details check pdf file. US5191350 LOW WIND LOAD PARABOLIC ANTENNA.pdf

Thats grid with dipole rear feed with splited coaxial balun, basic version (1) with one reflector on the feed

Diameters for a 1296MHz Hi, it looks very good! Could You try diameters for a 1296MHz? lambda 127.118644 lamda 231.481481 13cm(inch) 13cm(inch) 13cm(mm) alfa 23cm 2+1/2 2.5 63.5 0.49953333 115.632716 11/64 0.171875 4.365625 0.03434292 7.94974923 1+1/4 1.25 31.75 0.24976667 57.816358 1+27/64 1.421875 36.115625 0.28410958 65.7661073 1+3/32 1.09375 27.78125 0.21854583 50.5893133 2+7/16 2.4375 61.9125 0.487045 112.741898 3/16 0.1875 4.7625 0.037465 8.6724537 15/16 0.9375 23.8125 0.187325 43.3622685 2+7/16 02-Jan 61.9125 0.487045 112.741898

something about thos antenna from 1968 The Radio Amateur's V.H.F. Manual - A Manual of Amateur Radio Communication on the Frequencies Above 50 Megacycles 1968 https://dokumen.pub/the-radio-amateurs-vhf-manual-a-manual-of-amateur-radio-communication-on-the-frequencies-above-50-megacycles-11th-ed.html (I will try do my own for a 1296MHz) From the description, it seems that it is not a "simple dipole" but a slot antenna.

It is based on Pacyfic Grid 917x720 and 15cm deep 5.6GHz grid antenna symulation + Yagi Uda in revers - directors works likea rediators (This is not a good representation, Matlab has big limitations) 1296MHZ => 17.3dBi oryginal grid antenna https://www.cyberbajt.pl/produkt/350/pacific-grid-56-ghz28-dbi.html

I cannot find a commercial implementation of such an "feed" also no publication with "rear dipole feed with two reflectors". May the name is very specific, google does not return anything meaningful.

Thank You!, please give me few days to build this, i will show You the result

i like to try do such feed for a 1296MHZ, but I'm not sure about the dimensions, colleagues please tell me what would be the dimensions for a model with two reflectors. This one is too short, I modeled in matlab, resonance at 1500MHz (split coaxial balun):

That's my version of this antenna: (BOX completely incidental, should be other size) size 55x38x26cm bottom : 51x34cm

WOW! @Dr. Pepper You got 16dBi !!! I got only 14dBi I cant change angle of the box in Matlab, thats my limitation. I like to try it on 1296MHZ @AdminMay We have other section for 1296MHZ 23cm band antennas?

Thank YOU! I see the qain is smaller than I got, how it will be with 90deg, i belive that is possible to get 14dBi

"What else, what profit can it give." @Harry36 : I am curious with a bi-loop "in the box" I will be able to get more gain than a biquad, smaller in size, or a better shaped beam I don't have the tool to check this, Matlab antenna toolbox has some limitation. box diameters: 40cmx27cmx20cm +/- 1cm

Hi @Admin Could You Please symulate it for a 1296MHZ (23cm ham radio band)? I will try to cut this shape in laser from metal sheet. Thats my idea to add N or SMA connector. Lets fin out, how it will work with comparing to my biquads

in the simulation I achieved 14dBi. This brim is shallower than the simulation assumes, it could be 11.3 dBi. The antenna is very effective. I'm thinking of replacing the quadrates with loops. I'm thinking of a similar implementation as in the attached pictures, not laminate. @Harry36 Thank you for the clarification. With this antenna I am receiving ham radio beacon beacon SR6 LHZ 1296.830 with level -80dBm - distance 111 km, power 1W My aim is to increase the gain of a single biquad. maybe changing the shape or geometry will help. That is my antenna: