increase power of NRF24L01 radio - Page 1
Forum section: electronics / beginners

author: Unknown
author_rank: Unknown
timestamp: April 24, 2014, 10:31:18 am
content: POST REMOVED AT USERS REQUEST

author: Whales
author_rank: Super Contributor
timestamp: April 24, 2014, 11:04:58 am
content: Probably, but I'm not familiar with amplifiers in the Ghz. I assume they are costly and need strict canning & PCB layout.If your targets are not moving, using ahigher gain antennaemay be easier. The kiwis have excelled at using thisto pick up wifi from several Km away

author: Marco
author_rank: Super Contributor
timestamp: April 24, 2014, 11:40:46 am
content: How much amplification are you looking for? Elecfreaks has a version with small amplifiers (20 dB for transmit, 10 dB for receive I think).

author: 8086
author_rank: Super Contributor
timestamp: April 24, 2014, 12:04:37 pm
content: Sort of off-topic, but does anyone know why the Elecfreaks module only claims 1000m range in ideal conditions with +20dB gain, while the XBee Pro ZB claims 3400m range and +18dB gain?Is it simply a case of...better engineering? They seem to otherwise be the same or very similar (data rate, etc).

author: Whales
author_rank: Super Contributor
timestamp: April 24, 2014, 12:12:40 pm
content: Quote from: 8086 on April 24, 2014, 12:04:37 pm"Range" is non-scientific. It can be anything they want it to be, depending on many other variables.Antennae gain values are approximates AFAIK -- their exact patterns are more complicated than a cone model. *not an RF engineer*EDIT:Quote from: Wikipedia

author: 8086
author_rank: Super Contributor
timestamp: April 24, 2014, 12:35:41 pm
content: Quote from: Whales on April 24, 2014, 12:12:40 pmSo you reckon they are simply referring to different points on their radiation patterns?One being optimistic and one being conservative?Still seems like a huge difference in range, wouldn't you think they would both use their maximum value?

author: theatrus
author_rank: Frequent Contributor
timestamp: April 24, 2014, 02:32:05 pm
content: Chipcon/TI have a set of 2.4GHz LNA/PA combos which replace the balun for their radios. However it's going to be a bear making it work with the Nordic chip if you don't have RF experience and a VNA.Edit: though I distinctly remember having a coworker make this work well enough on a product. But we had a VNA to tune in the design.

author: ve7xen
author_rank: Super Contributor
timestamp: April 24, 2014, 08:04:03 pm
content: Quote from: 8086 on April 24, 2014, 12:35:41 pmMore likely their definition of "range" is just different. Does it mean "distance in free space at which communication is still possible with a < 50% error rate" or does it mean "distance in 'real life' conditions at which communication at full speed with low error rate is likely"? I'd guess one or the other has a looser specification on what the expected data and error rates will be at full "range".Anyway, you're kind of comparing apples to oranges here, since the XBee you're referring to is a ZigBee radio and the Nordic module is not. ZigBee is only 250kbps while the Nordic modules do 1mbit or 2mbit, this will add a fair bit of noise margin. The modems will also likely be implemented differently, and possibly the radios themselves have better (lower noise / more sensitive) receivers. This is clear from the specsheet sensitivity numbers - Nordic claims -85dBm at 1mbps, Digi claims -102dBm.Really these numbers are marketing wank though, not an engineering specification, they can practically just make them up. There are too many, and too loosely-defined variables to glean anything other than order-of-magnitude information out of them. What you need to do is measure (or look in the specs, if provided) and find out what the minimum signal strength at the receiver is that results in acceptable performance for your application. Then you can estimate your antenna gains & path loss and figure out what an approximate range for your usage is going to be.

author: 8086
author_rank: Super Contributor
timestamp: April 24, 2014, 08:10:41 pm
content: Quote from: ve7xen on April 24, 2014, 08:04:03 pmFair enough, I hadn't really considered that the radios themselves would make such a difference when the specs seem so similar.Am currently deciding on a ~1km range wireless solution for a project so maybe I'll get some of the XBees and some of these cheaper ones and see how they compare in real life...

author: theatrus
author_rank: Frequent Contributor
timestamp: April 24, 2014, 08:21:20 pm
content: http://www.ti.com/product/cc2591&lpos=See_Also_Container&lid=Alternative_Devicesis the front end LNA/PA.

author: theatrus
author_rank: Frequent Contributor
timestamp: April 24, 2014, 09:52:42 pm
content: Quote from: pereczes on April 24, 2014, 09:46:30 pmThen this level of RF work is probably not a project you are ready to tackle then. While it is a "small matter" of putting it on the board, all of the RF properties need to be considered, and this is not something you can measure simply with an oscilloscope.For the curious, the adaptation required an RF transformer-balun and impedance controlled work (as expected for an RF section)

author: Marco
author_rank: Super Contributor
timestamp: April 24, 2014, 10:13:40 pm
content: Quote from: pereczes on April 24, 2014, 12:31:48 pmhttp://www.elecfreaks.com/store/nrf24l01p-pa-lna-v20-p-142.html