ADS-B antennas, cheap chinese PCBs and the others

[abcd567]

This is continuation to my above post about side-by-side antenna testing, showing influence of RF noise existing at testing environment, and how filter substantially reduced this influence, and makes comparison fairly independent of noise at testing environment.

Scan 1 of 6 - FA Antenna + Generic DVB-T (No filter)

CLICK ON IMAGE TO SEE LARGER SIZE

 

Scan 2 of 6 - V-Stub Antenna + Generic DVB-T (No filter)

CLICK ON IMAGE TO SEE LARGER SIZE

 

Scan 3 of 6 - FA Antenna + ProStick Plus (No External filter)

CLICK ON IMAGE TO SEE LARGER SIZE

 

Scan 4 of 6 - V-Stub Antenna + ProStick Plus (No External filter)

CLICK ON IMAGE TO SEE LARGER SIZE

 

Scan 5 of 6 - FA Antenna + ProStick Plus + External Filter FA Light Blue

CLICK ON IMAGE TO SEE LARGER SIZE

 

Scan 6 of 6 - V-Stub Antenna + ProStick Plus + External Filter FA Light Blue

CLICK ON IMAGE TO SEE LARGER SIZE

 

[Nitr0]

Can we stick to antenna and not specific environmental/location noise issues? There is another thread dedicated to noise and filtering already. This doesn’t have a bearing on antenna comparisons as a whole. It’s an underlying issue that needs to be dealt with using other means.

[abcd567]

@Nitr0

Can we stick to antenna and not specific environmental/location noise issues?

Yes sure.

The environment issue was raised by @geckoVN when I asked about side-by-side test of PCB antenna and FA antenna. I have only replied to his post. Sure I am not going to reply if environment issue is raised again.

[Nitr0]

Alright, so being a glutton for punishment and for the sake of having a complete useless collection of cheap PCB antenna, on top of the ones I already have, I have orders in for the following:

Notched/Tuned PCB Antenna
and
LNA & filtered? PCB Antenna

While the notched is really no different than the 170mm board I already have (with a couple shortened traces), I’m curious how it specs out and does in comparison.

I’m really interested to see what components are on that $15 antenna. I know it has an inline LNA and will require a Bias-tee, but will be interesting if it’s filtered as well. Although, if that’s the case, I’d think the filtering would be before the LNA (on antenna side, not radio) as I don’t think the various SAW filters pass DC - hopefully the chips aren’t shaved and I’ll be able to trace it out and post here. Specs will be interesting and for $15, it could be a fantastic low-budget fix for many.

[abcd567]

ADS-B active receiving antenna 1090MHz

technical indicators

1. Operating frequency: 1090±15MHz
2. Passive gain: 2dBi (dipole antenna)
3. Antenna polarization: omnidirectional vertical line polarization
4. Active gain: 20dB
5. Out-of-band rejection: >30dB
6. Working voltage: 2.5-5.5V (skin negative core)
7. Working current: 80mA
8. System impedance: 50 ohms
9. Antenna weight: 15g
10. Dimensions: 20 × 170mm
11. Connector form: SMA standard female head (outer screw inner hole)
    
    

[abcd567]

ADS-B 1090MHZ Antenna

Description:
Model: ADS-B 1090MHZ antenna
Gain: 2.0dBi
Frequency range: 1060-1120 (MHz)

[Nitr0]

So they say…Looks a little too perfect to me.
We’ll get to the bottom of these things yet and only then will know if they are worth recommending after more tests.

[abcd567]

ADS-B 1090 MHz 12DB PCB Strip-line 4 Half-Wave Antennas SMA Female For Receiving Signals

[keithma]

@Nitr0

So they say…Looks a little too perfect to me.

The samples were made of unobtainium and when they put the design out to the manufacturers, they couldn’t find a reliable supplier

[geckoVN]

@Nitr0

If there are other versions …

Something to watch is that not all antennas sold for ADS-B claim to be 1090MHz

[Nitr0]

@geckoVN

Something to watch is that not all antennas sold for ADS-B claim to be 1090MHz

Good eye @geckoVN. I seen some in the 960Mhz range as well. Definitely need to pay close attention to that if/when ordering. Hadn’t seen 1030Mhz before. Why do they do that stuff. lol I guess they want to pickup the interrogations