Page 1 of 1

1090 Antenna real or Fake?

Posted: Sun Dec 09, 2018 1:38 pm
by Username
Hi
Everyone who travel from time to time on a plane know there is no better place to track other Aircraft. :D
The problem the Antenna must be "Stealth" to hide it behind a window shade. ;)
I found on Ali this: https://www.aliexpress.com/item/10-piec ... 9b767b65bf
https://www.aliexpress.com/item/5-dbi-S ... eee71477b8
https://www.aliexpress.com/item/10-dbi- ... eee71477b8

are the genuen or just relabled LTE Antenna?

Re: 1090 Antenna real or Fake?

Posted: Sun Dec 09, 2018 2:00 pm
by HighSNR
There is no way to tell without some sort of measurement. Many antennas I get from reputable brand name suppliers dont come close to meeting their performance specs.

Re: 1090 Antenna real or Fake?

Posted: Sun Dec 09, 2018 3:36 pm
by EmilK
I would say its a fake - the 10 db statement - my 10 db antenna has 1.8 m length. The one in your post has 37 cm.

Fake 1090 Antenna

Posted: Sun Dec 09, 2018 7:13 pm
by snn47
There is a difference between theoretical and real meassured gain, and here it is a placebo gain to bait buyers, because you can't cheat physics.

To give you an idea of the necessary size for an vertically polarized omnidirectional antenna with meassured 10 dBi gain look at https://www.kathreinusa.com/wp-content/ ... 715986.pdf. The active antenna length is about 1945 mm.

An increase in gain will either limit the beamwidth in azimuth or elevation, as you can see from the narrow elevation pattern.

Some antenna, e.g. 1/4 wave-length monopoles are smaller, but require a ground plane of sufficent size to operate, e.g. aircraft blade antenna for 960 - 1215 MHz, while small in size require a 4 ft by 4 ft as ground plane (source DME/SSR MOPS) see also L-Band receive antenna (960 MHz to 1215 MHz) viewtopic.php?f=6&t=1516 .

Furthermore in order to obtain the gain requires that an antenna is clear ob obstacles, any non-conductive and conductive in the direction to the source you want to receive, The closer they are to an antenna the more distorted the antenna pattern and the lower gain is.

Re: 1090 Antenna real or Fake?

Posted: Sun Dec 09, 2018 10:33 pm
by rtlsdrblog
The first one doesn't even have the right connector, it's using an RP-SMA connector meant for WiFi devices.

The whip type antennas are quite trash unless you're actually in a plane. Go for a FlightAware antenna or similar. Should still be small enough to hide behind a window.

Re: 1090 Antenna real or Fake?

Posted: Mon Dec 10, 2018 10:31 am
by Username
Which one?
I know only that: Image

Re: 1090 Antenna real or Fake?

Posted: Tue Dec 11, 2018 4:39 am
by rtlsdrblog
Username wrote:
Mon Dec 10, 2018 10:31 am
Which one?
I know only that: Image
https://www.amazon.com/1090MHz-ADS-B-An ... lightaware