Це відео не доступне.
Перепрошуємо.
YAGI Antenna explained - What is the difference between a Yagi and LPDA antenna?
Вставка
- Опубліковано 12 сер 2018
- Dr Andre Fourie explains what the difference between a YAGI and LPDA (Log Periodic Dipole Array) antenna is. Why is an LPDA a better option for 2G, 3G, 4G and LTE?
Specs here: poynting.tech/product/lpda-92/
or poynting.tech/antennas/lpda-500/
Want to talk to someone at Poynting contact us here:
South Africa: +27 12 657 0050 or info@intetoconnect.co.za
Europe: +49 89 7453 9002 or sales-europe@poynting.tech
USA: +1 817 533-8130 or sales-us@poynting.tech
Rest of the world: +27 12 657 0050 or sales-global@poynting.tech
Website: poynting.tech/
2021 June updated
I wish I had a lecturer like you in my university ... Very clear and fully comprehensible. Thank you sir
Thank you! So clear. We need more youtubers with PhDs!
Thanks:)
I Wish all instructors were as good as you are. Thank you very much.
Thank you very very much, Sir. before your video, I'm looking for designing a yagi antenna but you opened my eyes. Now I only want the LPDA antenna and I'm gonna design that very soon. Love you from Pakistan :)
This is exactly best short an understandable explanation between 2 antennas types. Thanks.
Learned something this morning. Very interesting. Thank you.
Wonderful mini lecture . Thank you.
Thank you. Very well described. Cleared up the mystery.
Pleasure
This is really interesting - Thank you a lot!
Thanks. Very nicely explained.
Great info, thx!
Excellent. I learned something. Very clear.
Thanks - please share where you can🙂
Great video, thanks for the information.
Glad it was helpful!
Nice explanation. I want the YAGI for OTA television.
Brilliant explaination, thanks
You are welcome!
it was helpful. Thank you
Pleasure Amir!
So I’m in a rural area surrounded by trees. The best thing for me is MIMO. I have a mofi450 attached is 2 yagi’s on a T bar and pole angled at 45 degrees. They are WiRengs super expensive antenna. These have worked decent but degrade easily about 10-12 miles from tower. Maybe -113 to -117 single strength. I bought two Log periodic antennas at 46 inches long I believe. Will these hold a better signal maybe lower db’s vs the yagis? Orientation of these on a pole would it be one on top
One on bottom spaced 3 feet? Would they or should they both be facing same tower and direction? Let me know I haven’t received yet I just want to ensure I have it set up the best way. I assume these combined will make MIMO. Thanks in advance video was very helpful and understanding!
When pointing a pair of LPDA at a single tower, do you advise orienting them at 0 and 90 degrees or plus and minus 45?
very informative.. thank you for this
My pleasure!
So and LPDA is kind of like a fan dipole, a bunch of dipoles with a common feed point and the signal magically finds the one that is most resonant and mostly ignores the others. Neat.
Thanks, very helpful :)
LPDA is for more than one band, Yagi for a single band.
So, do you use lpda for television?
most log periodic space the longer elements further apart than the short. Are they better than one where spacings are constant?
Does it matter if the antenna is installed flat or upright. All the ones I've are upright or is that just to stop birds landing on them? Thanks for pointing the way (absolutely no pun intended) in an easy to understand talk.
Superb explanation
Thank you 🙂 Will let Andre know!
Yagi and LPDA. I was guilty! I did not know there was a LPDA. Very COoL. Thank you.
Great - glad you are watching!
baie dankie
Plesier!
Awesome thanks
Welcome 😊
Awesome presenter
Thank you
LPDA is for radios and Yagi is for GSMs?
Thanks a lot! you sir really deserve a like! Are you related to the FOURIER? I mean, THE Fourier
And I just subscribed.
@@poyntingantennas sir did 16dbi LPDA will do better even nowadays 18dbi-21dbi+ exist
Hi! I live in an area where we are covered by mountains. Should we buy a parabolic antenna to have a good family use internet speed?
I am from Philippines and I'd like to try your products. Is it available here in our country?
4G LTE antenna how make
Can we use solid aluminum element 1cm in diameter to make 1/4 MHz antenna?
Thanks for your reply, I am going to use screws between the antenna elements to screw into the boom (like the arrow yagi antenna) I did not calculate the screws in my calculations Do I need to reduce the size of the haro element to use screws between the two elements? The two elements make the size of all the elements 2cm larger than the calculations. Am I having trouble?
Lpda vs delta loop, where is the best for gain (with same element)
@@poyntingantennas delta loop antenna full wave (1lamda, divided 3 sides) www.amateurradiosupplies.com/delta-loop-antenna-s/104.htm
Hi,
Can we use LPDA antenna for boosting mobile signals ?
@@poyntingantennas Can we use LPDA antenna in philippines
So for getting cellular signal. lpda antenna is a safer choice than yagi or grid parabolic antenna because is has a wide variety of frequency support?
@@poyntingantennas Is it true, theoretically, that the more antennas in parallel, the better? So 4 or even 100 LPDA's in parallel (or any antennae) to the same wire would result in a stronger reception? This boosts the voltage correct? Is a strong signal correlated to a strong voltage or strong current or both? So, theoretically, a longer (bigger) antenna with more frequency matched elements will boost the current and many spread out in parallel will boost the current? is there a limit to how many additional elements (length) and how many in parallel what will provide a stronger signal? Am I understanding the basics correctly?
@@VenturaIT Hi Ventura IT, every Antenna has a characteristic Impedance, without going into too much detail, that is the Inductive/Capacitive 'Resistance' which is very much Frequency dependent. The lengths and distances between the Dipoles that form the elements of the LPDA (Log Periodic Dipole Array) are very carefully calculated to present (in the case of most RF Comms) a 50 Ohm Impedance Load to the Transmitter (for example) of say the Router that will be connected to the Antenna. This means that one cannot connect two LPDA Antennas in parallel without interrupting the Load that it presents to the transmitter. Two 50 Ohm Antennas simply connected 'electrically' in parallel would (parallel circuit theory) half the characteristic Impedance (as well as the 'load') to 25 Ohms affecting the transfer of Power to the Antenna so, no, one cannot put LPDA in parallel without for instance matching Hybrid Splitters. The main issue with Splitter/Combiners is that you will 'lose' 3 dB of Power meaning only half the Power of the Output of the Transmitter will be 'presented' to the Antennas. Each Antenna that you add to that will need a Matching Hybrid Splitter (as an example of a splitter which maintains the characteristic Impedance to all the ports) to maintain the Load presented to the Transmitter for maximum transfer of Electromagnetic Energy (the 'Radio' Wave). The Electromagnetic Wave (Radio Wave) 'induces' a Current in the Dipole of the Antenna, at the resonant Frequency (Dipole length, to be simplistic) so theoretically , the more Dipoles you can 'fit' onto a Log Periodic Array, the better the 'wideband capability and the Gain of the Antenna will be. The Current induced by the Magnetic component is of course closely related to the Potential Difference (Volts) presented to the characteristic Impedance, the 50 Ohm 'load. Its a little more complex than that but that's the essence, The number of Dipoles is really limited by practical size and the 'number' of Frequencies (Wideband) you need to cover and the Gain of the Antenna you wish to achieve. I hope this is clear enough, if not please respond and I will endeavor to explain more, kind regards, Pieter Prinsloo, Technical Marketing Engineer, Poynting (Pty) Ltd.
@@pieterprinsloo1022 I just wondered if multiple small antennas at different locations would be better, you could have one up on a hill, one over in the valley, one at your house, etc... and tie them all into the receiver to get a better signal. I'm sure someone has tried a lot of small antennas wired together?
i want to build one for CB band :)
It's all about frequency
Why does one yagi have the folded dipole laying down and the other is standing up?
@@poyntingantennas there's no effect from phasing by laying the folded dipole down?
👌🇦🇺
can you compare a log periodic to LPDA?
@@poyntingantennas Hi Poynting, thanks to you I now learned that what I thought was a log periodic antenna is more specifically the LPDA and that there are other log periodic antennas. haha sometimes i'm a little bit stupid but thanks to people like you i get a little bit smarter every week ;)
A bit like a multi band antenna.
LPDA dc shorted antenna has a low termination impedance,Its a lumped constant impedance mismatch VSWR compared to a distributed 50 ohm coax feeding the antenna termination.A non dc shorted antenna(Yagi with gamma matching element)will have higher gain and electrons migrate better due to the center conductor is not dc grounded,Better electron mobility along the surface of a conductor.Ground potential is noisy with many frequency transients,As noisy as the atmospheric potential that is effecting it.Delta matching yagi antennas are dc grounded and do not preform as good as gamma matched yagi,But the delta matching has broader bandwidth.I took two of your poynting LPDA antennas (In a side by side stacked configuration)and cut the connection where the dc shorting stub would be and put insulators in between the 4 mounting holes to isolate the 2 sides of the antenna boom,Used delrin washers for the bolts so not to make contact from each side of the antenna boom,So now its a non dc shorted LPDA and it works much better in a remote area.Was working with under -110dbm's.I used a sawtooth sweep generator with a high end detector probe to sweep the antenna before and after and the parabola/Bell curve did change,The Q has a much higher skirt and it did narrow the bandwidth but with much more gain it makes up for the small loss in bandwidth.Many more peak nodes along the 700 to 1900mhz frequency range after the modification.Went from B2 -123dbm to -109 dbm and B12 -107dbm to -96dbm,With much faster down and upload speeds after the mod.My only concern is corona discharge effect since the center of the coax is not grounded.Next project is building a faraday cage reflector above the antennas.And sidactors on each connector of the router.I bought a military Log periodic antenna (50-900mhz) at a army base auction and at the C type connector,Its not dc grounded.Joe EE/P.E.
Great study. Not something we have ever looked into in that much detail - please keep feedback coming. Perhaps we can make some useful modifications
S that a South African accent?
Yes it is:)
The LPDA looks like a hedge shear.
@@poyntingantennas What intrigues me is how the LPDA manages to avoid phase shift and reflection and being resonant at different wave lengths at the same time even though the phases don't fit entirely together. On the other hand I expected that the slight phase shift would probably create coupled oscillation modes.