OMNI ANTENNA

[tharun 0]

Hi all,
I am currently working on a project where i have to transfer video signals to a distance of 10km. i want to know that can i use a omni antenna on one side and a directional antenna on the other side. reason for using omni antenna is that side is a rotating fixture .so we need 360 degree coverage. i want to know whether this will work and also if there is any omni antenna which can transfer video signals you can share the datasheet\part no.

[Admin 2713]

,,, maybe it would be interesting to see these...

https://www.lan23.ru/forum/node/340

https://deracahyono.wordpress.com/2011/02/26/isi-omni-built-up-hyperlink-15-dbi-review/

https://www.lan23.ru/forum/node/462?t=978

[Jayakumaran S 4]

On 3/23/2022 at 6:53 PM, Admin said:

,,, maybe it would be interesting to see these...

https://www.lan23.ru/forum/node/340

https://deracahyono.wordpress.com/2011/02/26/isi-omni-built-up-hyperlink-15-dbi-review/

https://www.lan23.ru/forum/node/462?t=978

sir i want to improve the omnidirectional antenna at 340MHz with gain of 25-30dBi, is it possible? , can you send any design images or design files that match with my spec, please help me sir.

[Admin 2713]

,,, with gain of 25-30 dBi,I think is not possible...!!!

[Jayakumaran S 4]

34 minutes ago, Admin said:

,,, with gain of 25-30 dBi,I think is not possible...!!!

thank you for your reply sir, please send any omni directional antenna source img or dwg files for improving the gain atleast 12-15dbi. 

[clanon 284]

On 5/27/2024 at 2:00 AM, Jayakumaran S said:

sir i want to improve the omnidirectional antenna at 340MHz with gain of 25-30dBi, is it possible? 

OMNIdirectional  and high gain  are MUTUALLY EXCLUSIVE can not have BOTH...at 340 mhz omni Vertical colineal VEEERY LOOONG could get you 15 dbi...using several meters of wire...

[Jayakumaran S 4]

On 5/28/2024 at 9:57 PM, clanon said:

OMNIdirectional  and high gain  are MUTUALLY EXCLUSIVE can not have BOTH...at 340 mhz omni Vertical colineal VEEERY LOOONG could get you 15 dbi...using several meters of wire...

sir i need omni within 500mm length and having the gain of 12dbi what can i do sir, i did array and metasurface , is there any other option to improve the gain sir. Thank you sir for your consideration. 

On 5/27/2024 at 10:36 AM, Admin said:

,,, with gain of 25-30 dBi,I think is not possible...!!!

thank you for your reply sir, please send any omni directional antenna source img or dwg files for improving the gain atleast 12-15dbi. 

[clanon 284]

12 dbi omni is doable...what wideband arround 340 mhz...? (Narrow = Wire  , Wide = Tube) but you gonna end up close to 5 meters having 44 cm each dipole... a big Tower...for omni...

[Jayakumaran S 4]

9 hours ago, clanon said:

12 dbi omni is doable...what wideband arround 340 mhz...? (Narrow = Wire  , Wide = Tube) but you gonna end up close to 5 meters having 44 cm each dipole... a big Tower...for omni...

sir i want slighty wider band(50MHz band width), i did array and metasurface , is there any other option to improve the gain sir.

[clanon 284]

you gonna need tubing (aluminum old  TV antennas) 10 mm or more...MOST Array aren't omni , metasurfaces are a LIE...VERTICAL FRANKLIN Collineal is the way...BUT MOST I see are folded dipoles with facing on the coax...SO a SIMULATION is NEEDED for ONE DIPOLE and then multiply by at least 6-8 or 10 units and facing  COAX should be calculated...for 340 MHZ and 50 mhz bandwith...

Edited May 31, 2024 by clanon

[Jayakumaran S 4]

On 5/31/2024 at 8:08 PM, clanon said:

you gonna need tubing (aluminum old  TV antennas) 10 mm or more...MOST Array aren't omni , metasurfaces are a LIE...VERTICAL FRANKLIN Collineal is the way...BUT MOST I see are folded dipoles with facing on the coax...SO a SIMULATION is NEEDED for ONE DIPOLE and then multiply by at least 6-8 or 10 units and facing  COAX should be calculated...for 340 MHZ and 50 mhz bandwith...

Dear Sir,

After a long gap, I revisited this website and designed an dual band 2.4GHz and 5GHz omnidirectional antenna based on approximate online dimensions. I attempted to set up a wave port, but encountered meshing issues.

I have attached the design file. Could you kindly help simulate the antenna?

Thanks in advance.

Omni_2.4GHz_5GHz.cst

[clanon 284]

First of ALL

BOTH Your Coax cable HAVE NO SHIELD...

Adding a SHIELD present a NEW problem (they would be DANGLING in the AIR -No Connected to ANYTHING)

Edited Wednesday at 12:25 PM by clanon

[clanon 284]

Those TWO collineal (2,4ghz) NEED an adapter to SHOW 100 Ohms in the middle (50ohms on coax)

Two identical antennas of 50ohms would give 25ohms in the middle not right

[clanon 284]

Those TWO collineal  NEED an adapter to SHOW 100 Ohms in the middle (50ohms on coax)

Two identical antennas of 50ohms would give 25ohms in the middle not right

I ran one alone and is promising...

[Jayakumaran S 4]

20 minutes ago, clanon said:

Those TWO collineal  NEED an adapter to SHOW 100 Ohms in the middle (50ohms on coax)

Two identical antennas of 50ohms would give 25ohms in the middle not right

I ran one alone and is promising...

Thank you so much sir, could you please send this corrected design file.

And where i can see the OHM stuff in CST.

[clanon 284]

18 minutes ago, Jayakumaran S said:

 could you please send this corrected design file.

And where i can see the OHM stuff in CST.

Still workin on it (good antennas BAD FEED NETWORKS !) I'll upload it if it works give me time

After the simulation is OK on Port impedance Z (should be 50 ohms ) Electronics = Cables= Antennas (50Ohms=50Ohms=50ohms)

Edited Wednesday at 01:45 PM by clanon

[Jayakumaran S 4]

14 hours ago, clanon said:

Still workin on it (good antennas BAD FEED NETWORKS !) I'll upload it if it works give me time

After the simulation is OK on Port impedance Z (should be 50 ohms ) Electronics = Cables= Antennas (50Ohms=50Ohms=50ohms)

I'm glad to have found this website and your support. While I can handle complex designs, I struggle with port assignment and impedance.

I look forward to learning from experienced people like you. I’m truly grateful to you sir thank you.

[Admin 2713]

,,,must add ground to coaxial cable...!!!!

 

[Jayakumaran S 4]

48 minutes ago, Admin said:

,,,must add ground to coaxial cable...!!!!

 

Many thanks for pointing out the need to add ground to the coaxial cable.

Your advice is truly valuable sir.

[Admin 2713]

,,,,where did you get this project from...???

[Jayakumaran S 4]

20 minutes ago, Admin said:

,,,,where did you get this project from...???

Actually, my friend worked on this design in HFSS and shared the dimensions with me.

He mentioned that some of the values were taken from online sources, while the rest were based on approximations.