What is meant by ‘active’ ?
@bvdbrule, this antenna has got some cutouts. The antenna I used does not have these and resonates at about 1070MHz, the sleeve needs to be a bit shorter to get to 1090MHz. That’s probably the reason why they made these cuts.
@kylix, the active version probably also has a filter implemented. Good for ADSB, but not for LoRaWAN.
@LoRaTracker. Active means “with preamplifier”, probably with power via the coax.
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By the way, my tuned ADSB antenne works quite nicely from behind my rear view mirror. Better than the untuned dipole I used before. That dipole turned out to be to short and needed to be extended about 2cm on each end.
Here an impression of my route to work. I use 20dBm@SF7.
Be interesting to see how much the “preamplifier” improves reception. With LoRa operating well under nosie level it needs a good quality LNA to improve things.
I do experiment with an added Minicircuits PSA-5043+ and a 868MHz bandfilter. For now I’ve only seen higher RSSI levels, the C/N-values are about the same. I do use a short good quality coax, people with longer cables would probably benefit more. Down side is that I can not transmit downlink messages anymore, or else I will blow up my preamplifier.
Without a proper implementation to get statistics from the gateway I can not give any conclusive statistics yet. And it would also be nice if BEACE103 would come online again.
Eerrrm…illegal in NL/EU?! (unless cable and losses >4-6db giving EIRP <16dbm (14dbm +2.15dbI ant)) 
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I doubt my antenna has 2.15dBi gain. The antenna Q is not high enough for that. Gain is likely in the negative ranges. And I have some (semi rigid) coax and connector losses. I might be a bit over the 16dBm EIRP limit, but not much. To compensate I always use SF7 and only 19 bytes per message. 
Good day,
I need to order a couple of Antenna and I have some doubt about the Antenna requierement, specialy about the gain.
I am used to with 2db antenna https://shop.imst.de/wireless-modules/accessories/19/sma-antenna-for-ic880a-spi-wsa01-im880b-and-lite-gateway but I guess, there is restriction about de dbi?
Can I use a more powerfull antenna of 3 or 5 dbi? I hert than 2db is a good range. By digikey, I can found several antena with positiv and negatif dbi. So I am confused about what to choose if wither is there a limitation about dbi.
In my cas, the nodes are in orchard at about 1km of the gateway. One can transmit but not the second. Excepted of the small apple tree, there is no a lot of obstacle, but I would like to make sure that the node can transmit in a distance of 3-6km, (or more) .
Then I was thinking to buy some antenna more powerfull. As for exemple:
https://www.digikey.ch/product-detail/fr/linx-technologies-inc/ANT-868-CW-RCS/ANT-868-CW-RCS-ND/1942299
That a good idea?
Cheers
The only (legal) purpose I can see for a gain antenna in a TTN setup is in overcoming connector and cable losses, but then its just easier and cheaper to increase the gateway TX power level to compensate.
Can I use a more powerfull antenna of 3 or 5 dbi?
Sure, but remember to reduce the transmit power in the Gateway setup to ensure you stay legal.
You soon realsie that adding a gain antenna and reducing the output power(to stay legal) puts you back to square one and you dont have extra distance.
Hello
Thank for your reply.
What is the limit of the legal for Europe (France and Switzerland) There is knew recommandation.
I looked again on Digikey the Antenna. I found antenna with -2dbi and 2dbi. For wath are user the -2dbi antenna?
(As I am not realy sure about the gain reglementation, I will stay with 2dbi and not increase it)
Its assumed, in the UK at least, that the 14dBm power limit applies when using a +2.1dBi antenna.
Not sure if the limits apply to each and every possible European country, and neither do I have an intimate knowledge of the French and Swiss regulations …
put a link to one, but likely they are very small antennas to be soldered on the board of a node. Not always you need extreme gain and distance, size sometimes matter more.
Hello!
Excpeted if I am wrong, in Switerland the powerlimit is 14dbi, as well. I then suppose, I can only use 2dbi antenna.
Here are the antenna I found and not sure about what to choose
2.1dbi: https://www.digikey.ch/product-detail/fr/linx-technologies-inc/ANT-868-PW-LP/ANT-868-PW-LP-ND/1962850
2dbi: https://www.digikey.ch/product-detail/fr/abracon-llc/AEACAC053010-S868/535-14819-ND/9962430
-2dbi : https://www.digikey.ch/product-detail/fr/linx-technologies-inc/ANT-868-PML-UFL/ANT-868-PML-UFL-ND/5592353
-2dbi : https://www.digikey.ch/product-detail/fr/linx-technologies-inc/ANT-868-PML/ANT-868-PML-ND/1769747
But I suppose, the -2dbi is not what I should buy.
Mmm… forget my comment, those are not SMD mounted antennas. And honestly it seems strange to me that they declare lower gain. Wait for a real expert in this matter 
I would suggest, before you increase antenna gain do the following.
- Reduce losses on both the nodes and the gateway antenna connections.
- Add a matching network on the nodes if you can.
If those don’t work, then get better antennas. Often many antennas to not perform to their rating. However I have been able to achieve 5.9KM with this design from Texas Instruments. http://www.ti.com/lit/an/swra227e/swra227e.pdf
I can share gerber files of the antenna and matching network, then you can order PCB from your preferred vendor. All you need is solder on connectors and 1 SMD capacitor + 1 SMD Inductor and you are good to go.
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Hello, Thank a lot for your reply. Yes I am interrested about your gerber file. I am curious to see it and a such antenna will be very usefull for my next project.
I am not na expert abour antenna, but what do you mean by reducing losse.
The Texas Intrument antenna has apparently a db of 3-4dbi, that’s correct.
Last wueation what the real diffrérence with a such antenna https://shop.imst.de/wireless-modules/accessories/19/sma-antenna-for-ic880a-spi-wsa01-im880b-and-lite-gateway, excepted that your antenna can not be used outside. Then if I place into a plastic box, there is some recommandation about the material and the thickness to avoid doing an obstacle to the RF?
Great, thanks a lot
There is a loss at each connection point. Could be 0.5dB or more depending on the quality of the connectors. Reducing connectors, removing pigtails or reducing their lengths will help reduce these losses. Given the low power levels LoRa operates, such seemingly minor losses could be significant.
I will share a link to the Gerber later.
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Great! Thank a lot
Hi @pierrot10,
Click Here for the link to the antenna design files. You can download the gerber and BOM.
This SMA connector should fit the board …
And this male to male connector should allow you connect to existing nodes without a pigtail.
I usually integrate the antenna design on the same PCB with my node so the need for connectors and associated losses are eliminated.
Good luck