How to Increase Bluetooth Module Work Range

Some customers bought wireless Bluetooth transceiver modules to use and found that the transmission distance could not meet their requirements. There are many factors affecting the communication distance of the Bluetooth module. In fact, you can try to improve it. How to increase the working range of the Bluetooth module?

1. Power Adjustment

Starting from the power supply, wireless Bluetooth modules are quite sensitive to power noise, especially to glitch voltages and other high-frequency harmonics. If a proper power supply is not used to eliminate noise, it will inevitably cause voltage burrs on the power line, which may reach the RF power pin and affect the RF signal.

The wireless Bluetooth module is also a load and needs to dissipate a certain amount of power consumption. When selecting the power supply, it is necessary to consider whether the power supply capacity of the power supply is sufficient for the wireless module and other power-consuming units, and at the same time ensure a certain margin (at least 30% margin).

Therefore, when planning the Bluetooth wireless transmission products at the beginning, make a little adjustment in the power supply, and select a power supply chip with a small ripple factor and a suitable load current as the power supply unit of the wireless module to ensure the stability of the wireless transmission system. The work range will be longer.

2. Antenna

The gain of the wireless communication system is equal to the sum of the transmit power of the Bluetooth module and the gain of the antenna, so the gain of the antenna has a great relationship with the work range of the Bluetooth module. When the module matches the antenna, the antenna’s gain will be higher, and the Bluetooth module work range will be longer.

The general small suction cup gain is only about 2.0dBi, and some better outdoor large antennas can achieve a gain of about 5dBi. If the effect of data transmission with a low-gain antenna and a wireless module is not satisfactory, you can replace the antenna with a higher gain, and the Bluetooth module will transmit farther.

At the same time, it is also necessary to pay attention to the directionality and installation method of the antenna. The antenna should be erected as high as possible, and the antenna connected to the Bluetooth module should be placed in the same horizontal plane and parallel state, so that the sensing surface of the Bluetooth signal transmission and reception is the largest. The received electromagnetic wave signal strength is the largest, so that the Bluetooth work range is longer.

Currently, HYXKIOT has many Bluetooth module with antenna, the Bluetooth audio module HY-BT301C has PCB antenna, the Mini BLE 5.1 module HY-MOD02 has ceramic antenna

3. Transmitter and receiver adjustment

First of all, you need to consider the application scenario and determine the distance to be transmitted. If a long-range transmission is required, consider whether the Bluetooth module has a power amplifier (PA) and a low noise amplifier (LNA). Otherwise, long distance Bluetooth transmission cannot be achieved.

4. Transmission path

The wireless data communication of the Bluetooth module is realized by the linear transmission of wireless electromagnetic waves in the air, so the blocking of obstacles has a great impact on the Bluetooth transmission, especially the obstacles of metal objects, not only block the signal transmitted by the Bluetooth, but also absorb the Bluetooth transmission. And reflected electromagnetic wave signal, reduce radiation efficiency. Therefore, the biggest obstacle to Bluetooth transmission is actually metal, houses, woods, grass, sea level and other objects that can block.

5. Structural

For the case where the antenna is placed in the casing, it is suggested that, if the structure allows, placing the antenna outside the casing can increase the radiated signal strength and increase the transmission distance. Under the conditions that the structure does not allow, adjust the matching between the antenna and the module to increase the gain of the entire transmission system.

At present, most HYXKIOT modules support external antennas, such as HY-BT102 for Bluetooth dual-mode module, HY-BT301C for Bluetooth 5.1 audio module and HY-BT401 for BLE module.

6. Working Frequency

Wireless channels are relatively crowded, especially in the ISM frequency band. During the actual installation of communication equipment, spectrum surveys can be made on the local electromagnetic environment to select relatively “clean” frequency points to avoid unnecessary interference. At the same time, strict compliance with Local laws and regulations for frequency planning.

Communication distance is a comprehensive indicator of wireless modules, which is affected by many conditions, factors and parameters. In general, the wireless transceiver module should achieve the ideal wireless transmission effect.

Summarize:

①Do a good job in the early planning and selection, mainly for the power supply and the Bluetooth module to be used

②At the placement point of the elevated antenna at both ends of the transceiver or the placement point of the offset antenna, reduce the occlusion of obstacles, reduce the attenuation of the electromagnetic wave signal, and reduce the blind area ofthe Bluetooth signal

③It is recommended that the antennas of the transmitter and receiver be placed in the same horizontal plane and parallel to each other.

④Use high-gain antennas that match the Bluetooth module and match the user's application scenario