clanon

FR4 EATS 5ghz energy PES and copper tape would be MORE EFFICIENT . ALL METAL even better

coax specs might be off

could you post a .stl (cst2019 here)

different solver and different settings would give different F resonance . BUT dielectrics play the BIGGEST ROLE...try higher dielectric constant WHAT THICKNESSES ? METAL moves fr UP ussually is 0.035 mm copper 1.53mm FR4

Been beating around the bush for years to find a Good 4x4 patch array... Higher than 21 dbi , good impedance through the whole band,low enough vswr, under -20dbi side lobes... the original design is for 12,5 ghz and almost none side-lobes Power distribution Ratio 1:5:5:1 Changed it to WiFi , distribution ratio 1:1:1:1 (Original design Eliminated Sidelobes at the COST of 1,5-2dbi of gain) I'm happy (some testing still needed ) REAL dielectric constant of Polystyrene foam is a guess (1.02-1.05)

Only way I see to increase gain...is a reflector (Not omni anymore , but could add 3dbi) (multiplying elements cuts down on bandwidth and impedance changes)

the slits slots must be for wideband impedance matching...for FR4...

THIS dual band could be easier...FR4 moderate gain is for 2.4 and 5.2 but could be TWEAKED i think...

USE POLYSTYRENE FOAM (STYROFOAM) Low density as a spacer ,is TRANSPARENT to RF and have NO LOSSES

PORT ISN'T THERE , dangling (not touching metal on BOTH SIDES) or wrong port...CHECK WARNINGS

http://wifipanelantenna.blogspot.com/2008/12/panel-wifi-antenna.html 1800.cst

Different SOLVERS give Different Center Frequency (Frequency vs Time Solvers)

thinking about 15dbi or more by adding a reflector...Sectorial...

could any of you post a stl stp file ? (cst2019)

DIELECTRICS usually , radome adhesives...All add up in this case sustracts...

10 db is when losses are at minimum for both Spillover and illumination...

I think he means -6 db lobe pattern guarantees good efficiency for shallow dishes (with -4 loss at the border)

The shape of the main LOBE IIRC at -6 db affects efficiency...

Trying to make a "GOOD" Lpda , SCIFI VIVALDIs from RFSPACE have NO GAIN (under 1GHZ) , Chinese LPDAs have LOTS of LOSSES and mismatch...50 ohms FLAT ALL band , just a peak close to 1ghz unavoidable on this antennas...

https://ntrs.nasa.gov/api/citations/19670009367/downloads/19670009367.pdf

narrow band apparently

Looks like you have a resonance , DEEP, at 2.8... try making the whole Yagi 1.16 times bigger...

FR4 version...not so good...High losses and some mismatch , lower gain... fr4.dxf

Feed line on FR4 needs to be THINNER 5 mm or less...to get 50 ohms...