Can i reach the maximum BLE 4 range with these configurations ?

[Tizana]

Hi,

i'm designing a board based on NRF51822-QFAC chip and i'm using this antenna chip 2450AT43A100E and this balun 2450BM14E0003T .

I put the balun as close as possible to the NRF51822 and i choose the width track to be equal to 50 ohm using the Coplanar waveguide calculator.

above is a preview of the antenna / balun ....

and i'm planing to tune the antenna after the board will be assembled.

my questions are :

1/ can i get the maximum range that the BLE can have with this design ? is the antenna tuning ,that alows us to determine the pi network values, is enough to get the maximum range ?

should i make any hardware change ? like changing the antenna for a better one ?

2/ is there any software modification that i can make to enhance the antenna signal power ? i remember reading some member here talking about changing the signal power of the nrf.

3/ i'm planing to hand soldering the board and then tune the antenna to determine the PI network values. is that OK ? i mean the hand soldering won't be different from the pick and place machine and hence getting a false pi network values when making the final product ? let's suppose that the hand soldering are made by a professional and are well done.

4/ the board will be putted inside a case. the case is aluminum in the TOP where the antenna will be placed and plastic in the bottom side. did the aluminum case affect the signal strength ?

5/ for the pi network i choose a 603 component size because the 603 width component match with the 50 Ohm trace width of the antenna that i calculated (see image above).

so i'm worrying if i choose a 402 component they will be too small compared to the trace width. is that correct ? can i use a 402 component without any issue ?

Thanks,

[FormerMember]

1/ can i get the maximum range that the BLE can have with this design ? is the antenna tuning ,that allows us to determine the pi network values, is enough to get the maximum range ?

The maximum possible range for BLE depends on a lot of parameters. What I would recommend you to focus on is the maximum possible range for your design.

The antenna you are using looks fine, but it should be mounted like described in the antenna datasheet, 90 degrees on the ground plane, now it's placed 180 degrees, along the ground plane.

It should work fine to use the balun you are using. Note that it is important that the distance from the chip to the balun and the distance from the chip to the 2.2 nF capacitor is exactly the same as in the balun datasheet.

Ground is also very important, it is important to have as large as possible solid ground planes. It can be useful to read the tutorial "General PCB design guidelines for nRF51 series".

2/ is there any software modification that i can make to enhance the antenna signal power ? i remember reading some member here talking about changing the signal power of the nrf.

For maximum range, you can set the device to use maximum output power, +4dBm. For a mximized range, both sides of the link needs to have approximately the same output power. If one of the devices in a link has lower output power, that device will limit the range of the link.

3/ i'm planing to hand soldering the board and then tune the antenna to determine the PI network values.

Hand soldering works fine.

4/ the board will be putted inside a case. the case is aluminum in the TOP where the antenna will be placed and plastic in the bottom side. did the aluminum case affect the signal strength ? Metal (aluminium) will reflect the signals, and thus affect the range. I would recommend you to place the antenna outside of the metal part of the casing. Or, alternatively do testing so you know the compromise in range when using a metal casing top.

5/ for the pi network i choose a 603 component size because the 603 width component match with the 50 Ohm trace width of the antenna that i calculated (see image above).

It works fine to use 0603 components in the matching network for the antenna.

[Tizana]

thanks for all the answers but i still have a doubt about the 5 th question :

i want to use 0402 components instead of 0603 to reduce the track at it maximum, but i choose first the 0603 because the component width is the same as the 50 Ohm track !! so can i use the 0402 without affecting the performance ? see picture 2 in the question 5

another question : if i coded my program for the NRF51822-QFAC (48QFN), if i change the chip to the NRF51822-CFAC (62WLCSP) should i keep the same code i made for hte 485QFN or should i made some modification to my code ?

[FormerMember]

I don't think 0402 components will degrade the performance, we do also use that, even though the line may be slightly wider.

Yes, you can use the same code for those two chips, just double check the pin assignments.