Specifications

RF-BM-4044B2
www.szrfstar.com Ver1.1 - Aug., 2018
Shenzhen RF-star Technology Co., Ltd. Page 11 of 13
Layer, the copper must be spread on the connection part of the top layer and the module, and be close to the digital
part of module and routed in the Bottom Layer (all copper is well grounded).
5. Assuming that the module is soldered or placed in the Top Layer, it is also wrong to randomly route the Bottom Layer
or other layers, which will affect the spurs and receiving sensitivity of the module to some degrees;
6. Assuming that there are devices with large electromagnetic interference around the module, which will greatly affect
the module performance. It is recommended to stay away from the module according to the strength of the
interference. If circumstances permit, appropriate isolation and shielding can be done.
7. Assuming that there are routings of large electromagnetic interference around the module (high-frequency digital,
high-frequency analog, power routings), which will also greatly affect the module performance. It is recommended
to stay away from the module according to the strength of the interference. If circumstances permit, appropriate
isolation and shielding can be done.
8. It is recommended to stay away from the devices whose TTL protocol is the same 2.4 GHz physical layer, for
example: USB 3.0;
9. The antenna installation structure has a great influence on the module performance. It is necessary to ensure the
antenna is exposed and preferably vertically upward. When the module is installed inside of the case, a high-quality
antenna extension wire can be used to extend the antenna to the outside of the case.
10. The antenna must not be installed inside the metal case, which will cause the transmission distance to be greatly
weakened.
4.5 Trouble Shooting
4.5.1 Unsatisfactory Transmission Distance
1. When there is a linear communication obstacle, the communication distance will be correspondingly weakened.
Temperature, humidity, and co-channel interference will lead to an increase in communication packet loss rate. The
performances of ground absorption and reflection of radio waves will be poor, when the module is tested close to
the ground.
2. Seawater has a strong ability to absorb radio waves, so the test results by seaside are poor.
3. The signal attenuation will be very obvious, if there is a metal near the antenna or the module is placed inside of the
metal shell.
4. The incorrect power register set or the high data rate in an open air may shorten the communication distance. The
higher the data rate, the closer the distance.
5. The low voltage of the power supply is lower than the recommended value at ambient temperature, and the lower
the voltage, the smaller the power is.
6. The unmatchable antennas and module or the poor quality of antenna will affect the communication distance.
4.5.2 Vulnerable Module
1. Please ensure the supply voltage is between the recommended values. The module will be permanently damaged
if the voltage exceeds the maximum value. Please ensure the stable power supply and no frequently fluctuated