SparkFun Forums

[slide]

Hi, I am looking to get the nRF24L01 to reach a MAX range of about 6ft. What is the range on that ceramic pcb mount antenna? I would rather go for something cheaper, would one created on the pcb work?

[RonnyM]

You could probably achieve 6 feet with a 50 ohm resistor in place of the antenna! I have a client app which needs range around that. I originally used the chips, but range on the lowest power with receiver in most insensitive mode was about 12 feet. I removed one of the chips, and attached a 3/4" piece of wire. That did it! Attach a 1" piece of straight wire to both boards. That will give you plenty of range, or do a PC trace of about that length with no ground plane beneath. These little chips get good range without the fancy chip antennas. For a commercial app, you need to pay attention to spectral response and need a resonant antenna length. For a home project, there is no such constraint.

Ron

[slide]

Thanks! Where could I find information about spectral response and resonant antenna length?

[stevech]

You may want to use a "chip" antenna. These are SMD, about 1/2 inch square. The vendors for these publish the antenna patterns.

Antennas for these embedded radios are often just 1/4 wave wire.

[RonnyM]

I believe a 1/4 wave wire is 27 mm or so in open air(?) Leon?. A PCB trace would be shorter due to the dielectric constant of the PCB material. Before I had a spectrum analyzer capable of this frequency, I would solder a wire antenna in that was about twenty five percent too long, and take little snips off it while I range tested. Crude, but very effective. The Chipcon part has a RSSI register to make this easier, the 24L01 on the other hand, will be a fail/ success trial and error.
Ron

[andersonj55126]

I get about 30ft from nRF24L01 and chip antenna. Max power settings.

[RonnyM]

I get about 30ft from nRF24L01 and chip antenna. Max power settings.

Are you using the Sparkfun board???
The Sparkfun boards with the chip antennas were not designed properly. They had a ground plane under the chip which is a big RF no no. I was getting 100 + feet indoors with the Antenna Factor chip antennas. I have not tried a LOS test outside, but it should be at least double that.
Ron

[andersonj55126]

I used my own design using ANT-2.45-CHP. Has anyone tried a different chip antenna?

[RonnyM]

I used my own design using ANT-2.45-CHP. Has anyone tried a different chip antenna?

If that is the AF part, it is what I use. My test units do not have PTH holes under the 24L01 and all ground connections are to the side of the chip.I have been quite surprised with the range of the units, but, I only send a few bytes at a time. How many bytes do you send per packet? I have found the wireless network at work limits the range of the units if they get too close. Just for fun, try other channels.
Ron