NRF51 with PTR5518 range problems

[tanja]

Hi friends,

I'm using a NRF51 IC with this 4.0BLE Modul PTR5518 and i have big problems with Range. As a protocoll i use gazell. In air it is possible do get some correct signals up to 6-7 m but that it don't work properly anymore. If you have a human body in between it is a disaster, you only get good signals with a range <1m. Can i somehow approve this? Please help me if you can. I'm very desperate.

Thank you in advance. Tanja

[tanja]

Dear Jorn,

thanks for your answers, here the comments to your points (additional answers):

1. We tested with the gazell standard code without our Remote PCB and it has the same result from Range point of view and also when we shield the module like the HS Remote before.

2. I created already the acccount on nordic page, i will talk with the support if they can evaluate my design.

6) ) in the picture you can see the actual measurements (Description of the graph: 1) green line: appr. 3 m away from the Chamber antenna, operated from a person, / 2) red line: 180 degrees rotated: Person is now in between the Remote (distance remote and person 30cm) and the antenna from the chamber / 3)dark green line: 180 degrees rotated Remote near body (distance remote and person 0cm) / 4) brown line: 180 degrees rotated Remote near body (distance remote and person 0cm) shielded also with the second hand.

7. With completely covered you mean, when you cover it with hands? Have you ever used this PTR5518 from Xungtong? Have you also made some tests with this module?

Best Regards & thank you Tanja

[Jørn]

Since you get the same results with the sample code I think it is best you create a mypage task, provide detailed documentation of your design and refer to this case. I suspect there might be a hardware issue somewhere, such as impedance mismatch between the radio chip and the antenna.

Unfortunately I don't have any experience with that specific module. I have done my tests using two pca10028 nRF51 development kits. The devkits are fitted with the nRF51422, whose radio module is identical to that of the nRF51822 which is mounted on the Xungtong module. When I covered the antenna I completely covered the pcb trace antenna with my hands and made sure I was standing between the two radio modules, blocking line of sight.