This post is older than 2 years and might not be relevant anymore
More Info: Consider searching for newer posts

Regarding nRF51822 RF Performance

Hi All.

I am doing a BLE based project using nRF51822. My project is a Proximity Application. Where my device need to talk with an iPhone where I need around 150 Feet (Line of Sight) of Proximity Range. I used in my design nRF58122 QFAA Package and the below RF Parts:

Fractus Chip Antenna FR05-S1-N-0-102: www.fractus.com/.../DS_FR05-S1-N-0-102.pdf

Johanson Balun 2450BM14A0002: www.johansontechnology.com/.../2450bm14a0002-matched-balun-for-nordic-nrf24l01nrf24l01.html

I know Balun BAL-NRF01D3. is the best choice but I am not able to select it due to soldering difficulties.

I found the Chip Antenna FR05-S1-N-0-102 efficiency is good, 72% so I chooses it.

I checked on the nRF Antenna Design guide. Here as I used a ready made Balun so I think there is no other necessary to tune the antenna network as Balun is doing it. Please advise if I am wrong.

I found there are many nRF51822 Modules in Market with long BLE range. Like RFduino Module range I found on web search around 500 Feet (Line of Sight). So I thought my project also can get at least 150 Feet. But unfortunately I am getting only around 3 Feet ...

I used the nRF51822 Internal LDO Schematic Model. I have attached the Schematic and PCB RF trace picture.

Please advise me how to improve the range in such condition to achieve 150 Feet.

Looking forward your suggestion.

Regards.

Schematic_RF.JPG

PCB_RF.JPG

Parents
  • Hi Kristin.

    Thanks for detail reply.

    I redesigned the PCB and did not use the Balun this time. I used the discrete components (L and C). With new PCB I am getting range around 5M to 7M though my expectation is at least 30M (LoS).

    I like to ask,

    • For the RF design based on Discrete components looks like have a PI Model itself (Please see the attached). So to tune Antenna an additional PI Network needed?

    • I am also planning to make another design using Johanson Balun and PI Model. Do you think, its possible to get 30M Range (LoS) with proper PI Values? Sorry that I can not use the real Balun BAL-NRF01D3 due to its LGA and I am not able to do the assembly.

    Yes, with WLCSP room can saved. But for assembly issue I need to stay with QFAA.

    Thanks in advance.

    Regards.

    PI Network.jpg

Reply
  • Hi Kristin.

    Thanks for detail reply.

    I redesigned the PCB and did not use the Balun this time. I used the discrete components (L and C). With new PCB I am getting range around 5M to 7M though my expectation is at least 30M (LoS).

    I like to ask,

    • For the RF design based on Discrete components looks like have a PI Model itself (Please see the attached). So to tune Antenna an additional PI Network needed?

    • I am also planning to make another design using Johanson Balun and PI Model. Do you think, its possible to get 30M Range (LoS) with proper PI Values? Sorry that I can not use the real Balun BAL-NRF01D3 due to its LGA and I am not able to do the assembly.

    Yes, with WLCSP room can saved. But for assembly issue I need to stay with QFAA.

    Thanks in advance.

    Regards.

    PI Network.jpg

Children
No Data
Related