wireless communication distance?

I design a RX/TX circuit with nrf905 .and set the transmiter power +10dbm.But when the distance betweent the RX and Tx is above 2m,they can't commnicate.what may cause it?
thanks!

Hi...
Please check the interface between Transceiver and Antenna. I think you may be having loss in matching circuit. Also, please check if there is more than one transmitter in the receiver neighborhood.

check the received signal power and the receiver gain

Hi,

VDD_PA is tied to your Ant1/Ant2 Pin, If there's no problem with the soldering you can check that TX/RX antenna pin voltage is OK. You can also verify the signal at the RX antenna pin using spectrum analyzer. This will help you to know if your matching network is soldered properly. First measure the Rx input signal and try to resolder the matching circuit then measure it again.


Goodluck...

the antenna is connected correctly?

Make sure your T/R switch is on TX path rather than on RX path when you are tring to transmit power to another station.

Increase the receiver gain and boost the transmit power.

Have u calculated the link budget? Transmitting power is one factor in link budget. You have to find the antenna gain, sensitiivty of your test unit. Once you calcuate the link budget, you can find the distance

Added after 2 minutes:

Antenna is a critical part in the range, what kind of antenna you are using in the board?