SparkFun's Mariah Kelly Takes Some LoRa Antenna Types Out Into the Field for Some Range Testing
Taking to the wilds of Colorado, Kelly tries out three different antenna types: a patch antenna, a whip antenna, and a type N fiberglass.
SparkFun creative technologist Mariah Kelly has penned a piece looking at how antenna choice can affect the capabilities of LoRa radios — pointing you in the right direction for the best performance from your next long-range radio sensor project.
"A few weeks [ago] I posted a tutorial about how to set up a simple peer-to-peer network for sending sensor data over LoRa," Kelly writes. "During the process of that project I thought it would be fun to test the range of different antennas. It turned out to be quite and adventure (a bear even made an appearance!) to reach the outer limits of testing the range of a LoRa signal."
Kelly's attention was focused, naturally enough, on three types of antenna stocked by SparkFun for use with its LoRa radio modules: a low-cost patch antenna, a more expensive whip antenna, and a pricey type-N fiberglass antenna. Performance, unsurprisingly, follows suit — with real-world testing providing an idea of just how much range you can get from each.
"During our adventure out and about, we were able to get 1.45 mi[les] away from our transmitter (as the crow flies)," Kelly says of the wide-band patch antenna, a flexible piece of circuitry with a snort pigtail. "One thing to remember about LoRa is that line of sight, humidity, and obstacles are all things to take into consideration with your layout; we were able to find a few spots between buildings and breaks in trees to receive the signal, but having both antennas a bit higher up will likely extend this range!"
The whip antenna, by contrast, managed to reach 4.26 miles before losing connection — while the type N fiberglass antenna reached 6.42 miles, with a local mountain providing an elevation boost to help it see the transmitter on the roof of SparkFun's offices.
"Lastly, a safety tip," Kelly concludes. "Remember that if you hike up into the mountains of Colorado to keep an eye out for furry friends! With teeth! We saw this sweet lil' guy about 15 seconds after we got back in the car; a little too close for comfort, but we like to think he’s a big ol' nerd like us and wanted to check out what we were doing!"
Kelly's full write-up, complete with maps demonstrating the maximum range achieved for each antenna, is now available on the SparkFun blog.