Cannot find my Device on nRF connect

[bongjin jeong]

hello friends:) i have some problem during making my products, it's an a interface board with ble that generates UART signal for other board

and i made an schematic with reference design and i got my pcb and assembled it, but like picture 3; maybe -34dbm is my board, it can't load any informaion about it; chip is working that i checked with blinky application

someone says the antenna is problem... but i have no idea that what is a problem.. it really makes me mad.. pls someone help me....

[bongjin jeong]

circuit FOR here and no ground plane on bottom and via along antena are not connected

[Jørn]

I am not sure if a single shunt capacitor is enough for an inverted F antenna, or if you need a pi-network. This depends on the impedance of the antenna, it needs to be matched to 50 Ohm. All components and trace-lines leading out to the antenna must have a ground plane underneath, without this you will experience major loss.

The antenna must be surrounded by a solid ground plane. The ground plane is an important part of a PCB antenna. Any holes in the ground plane will affect the antenna impedance and resonance. I assume your vias are there to function as a via-fence, however they should be placed within a ground plane (not breaking the edge), and all of them need to be connected to ground on both layers. You should also make sure their parasitic inductances and capacitances don't make them resonate within your band. I also suspect your keep-out zone around the antenna is too small.