clanon

S11 is the measurement of the antenna (or any electromagnetic black box) of ABSORPTION and RADIATION (efficiency) It shows how "deep" RESONANCE is at a given Frequency and hence BANDWIDTH (Q factor) PS: first 1 is the energy out and the second 1 is the ENERGY in OUTput / INput = Efficiency It should be equal or bigger than -20 db

"Unfortunately, the use of low-cost FR4 as the substrate introduces some additional complexity on the antenna design. This is due to the inaccuracy of the FR4 relative permittivity and its high loss tangent (around 0.02). Variations in the FR4 electrical permittivity can shift the operating frequency and the high loss tangent dramatically affects the antenna axial ratio and gain, resulting in poor radiation efficiency." Design of Low-Cost Probe-Fed Microstrip Antennas | InTechOpen, Published on: 2011-04-04. Authors: D. C. Nascimento and J. C. da S. Lacava.

this guy gives WORSE numbers...

@5 ghz...anyway...it should be lower losses at 2,4ghz (couldn't find it...)

Neltec about 90% attainable...(-0.9151db) apparently

Not on DIELECTRIC...only on air ...i don't know about teflon...but for FR4 is 60 70 % efficiency...(-4.437 to -3.098)

Downscaled to 2.4ghz Dimensions guessed... 1mm teflon sustrate seems to work...need more refinements...to get higher efficciency and lower VSWR...and z closer to 50 ohms...(maybe...) It should get closer or more than 20.5 dbi...(@ 3.5 ghz...)

Haven't got "good" experiences with all parabolas y tried...(regular and offsets) Hard to point and adjust Feed... Wire (colineals) and Patch worked (better for me) If i need long range (more than 10km) i would go for the GRIDs (1m by 0.6) 24db or so...

it needs a 1:1 BALUN...imho (that dipole) The whole Thread (old)

PENCIL BEAM (hard to point it out)

The more dielectrics the more LOSSes...(efficiency is 65 % 70 at the best cases...) illumination losses , spillover... These antennas...without VOLUME and Diameter...never pass the 17 18 dbi...and most are a BITCH to point out...(But good for a POINT to POINT)

...only 14 dbi...(there are LOTS of plannars with that and more...(smaller , size and volume...) Nice dipole though...to use on a bigger DISH

SHORTED...to gnd REFLECTOR

TL -WN822N V1 AR9170 TL -WN822N V2 AR9287 (+ ar7010) TL -WN822N V3 RTL8192CU TL -WN822N V4 RTL8192EU TL -WN822N V5 RTL8192EU

Textolite 0.5mm 4mm from reflector.... 16dbi_no24.rar

You SHOULD start a NEW topic... LOVE HF , the ionosphere bouncing thing...Usually long WHIPS with correcting and load coils (maybe from front bumper side folded to cruise and free to rx or tx in a still)-slow position ...over here... but Long wire V and rhomboidals are best for RANGE PS: I could dig some ARRL info ...maybe (the older the better)

offset or regular...? By the way has anybody tried to put two FEEDs at 90 degrees on a regular dish (parabolic) ? (MiMo)...?

VERY INTERESTING info

Clone of this...? https://www.wifi-antennas.com/topic/227-tenda-o3/

The lens antenna is an array consisting of 680 rectangular waveguides arranged rotationally symmetrically around the antenna axis. The antenna operates as a concave lens, with an index of refraction n<1, which focuses the satellite signals and a reverse image of the Clark belt is projected at a focal plane behind the antenna. The concave properties of the lens ensures that the received plane waves are focused at one point. The phase of the waves is shifted forward in the waveguide, and the properties of the waveguides determine the shift. (Dielectric) There are two Fresnel zones in the antenna and, for each zone, the signal path to the focus is one wavelength longer than the previous one. The result is that all signals transmitted through the antenna reaches the focal point in phase. The circular symmetry of the antenna eases the control of the electromagnetic behaviour and reduces cross polarization. The media inside the waveguides is dielectric technical EPS with the effective permittivity S=1,1.(Expanded PolyStyrene) The dielectric makes the extremely thin copper waveguide walls possible with good mechanical robustness and it also allows a more compact construction as compared to air-filled waveguides. Satellite signals in a span of 36° can be received, which theoretically allows reception from 18 satellites because the required spacing between consecutive satellites is 2°. The receivers (LNBs) are placed on a focal line behind the antenna. Offset angle reception is of course very important in multi-satellite communication and a graph of the amplitude for different offset angles, at 12.25 GHz for the North American model, is shown in the figure below. The very low side-lobe levels help reduce disturbance from neighbouring satellite reception.

Metallic Lens Antenna Bell Labs 1946

Here's the problem...i think... CENTER FEED the DISC leaving the outer sleeve in the REFLECTOR...IMPEDANCE MISSMATCH!

Each wall (red brick) could take 5 db out , glass 2db s(depending on each glass) Cinder blocks (dry) up to 7dbs...You're supposed to rest this from Db of the router...or cover this losses with antenna GAIN... Sensitivity is much important than Power (is how good you listen and not how high you SCREAM) You could add a reflector on the back of your router...pointing to your area of interest...