865-868MHz Patch Antenna on PCB


(Jeff Uk) #21

May be a direct copy of the Semtech/iMST LoRaMote Mk1 PCB designs from 2014/2015…contact SMTC WSG Central Apps team or the guys at iMST - they may help…


(Henri C) #22

You’re right, it looks very similar! I’ve sent an email to know restrictions regarding the usage. I’ll post here if they give it to me and under which condition :slight_smile:


(Henri C) #23

Ok so the reference design is available on Semtech website as part of the Lora Community ressources. Direct link: https://www.semtech.com/uploads/documents/AN1200.20-SARANT_V1_0_STD.pdf

I asked the support to be sure and the design is free to use.


(Jeff Uk) #24

Yeh I forgot about the AN1200 series app notes - still have a copy of that one on file from years back…btw if interested there are others covering ref designs and the LoRa modulation basics etc. which may be of interest to anyone interested in LoRa background stuff (AN1200.19, .22, &.28 etc.), . The .20 incorporates a patch ant for use with the SX9500 proximity sensor for detection - use to adjust e.g. WiFi or BT (Or LoRa) Tx for meeting SAR requirements when close to body mass and also used with the original LoRaMOTE to put it into one of its prog/configuation modes (pinch patch during power up to trigger mode change :slight_smile: )


#25

https://www.ti.com/lit/an/swra227e/swra227e.pdf


(Arinze Izukanne) #26

I implemented this design in single mode. From all tests, with obstacles in the path, performance is very similar to a 1/4 wave dipole. However with a clear path i see a the PCB antenna RSSI better than that of a dipole antenna by at least 10units.

Here is a picture of both devices used in testing.

PCB%20Antenna%20Test


(Arinze Izukanne) #27

UPDATE
This is an update on testing the LoRa tracker device with a PCB antenna, same one I mentioned was very similar to a 1/4 dipole with an obstructed path (through walls). Apparently that is so only at close range. The previous tests were with a gateway indoors and the node at different distances from the building or within it.
However I got a pleasant surprise today, while driving around with the device to rest the range within the city. I received packets on a gateway 3.7Km away while driving with the device placed on a car seat and in an urban area. None of the devices I have used previously tested has been able to achieve this. The maximum distance has been approximately 1.8Km.

For most practical purposes, a good PCB patch antenna is more effective than any other antenna of equal gain as it completely eliminates losses due to connectors, couplers and pigtails.

DN024-Meadering%20Monopole