In the use of wireless module communication systems, many customers attach great importance to the communication distance, so how much influence does the external antenna have on the communication distance of the wireless module?
First of all, the editor prepares two DEMO demo boards (using our company's LoRoF30 demo board as an example), two 433 band antennas, and two 3.7V 1200mAh electric boards.
The editor connects the two DEMO demo boards to power and power, sets the DEMO demo board to the transmitting module and the receiving module, the frequency band is set to 868, the Code Rate is set to 4/5, the spreading factor is set to 12, and the bandwidth is set to 125KHz. Put it in the shielded room without connecting the antenna (the signal attenuation of our company's shielded room is -80dB)
Put the transmitting DEMO demo board in the shielding room, hold the receiving DEMO demo board in hand, and close the shielding room door, the TX and RX values of the receiving DEMO demo board do not change, and the communication is abnormal. The signal of transmitting and receiving DEMO demo board is not more than 1 meter away.
The editor connects a 433-band antenna prepared in advance to the DEMO demo board in his hand, the TX and RX values are accumulating, and the transceiver indicator lights flash normally. The wireless module communication returns to normal. The DEMO demo board in the mobile hand moves forward, the TX and RX numbers of the demo board in hand do not change, the sending and receiving indicator lights are always on, and the communication signal is interrupted. At this time, the DEMO demo board in the shielded room is about 26 meters away.
Next, the editor puts the 433 antenna on the transmitting DEMO demo board and puts it in the shielded room, holding the DEMO demo board in hand (without installing the antenna), and closes the shielded room.
When you reach the position where the communication signal was interrupted in the previous step, the communication signal of the DEMO demo board is interrupted at the same time. At this time, the editor connected another 433 channel antenna to the DEMO demo board, the values of TX and RX on the LCD interface changed, the transceiver indicator flashes normally, and the communication returns to normal.
Continue to move forward. When you reach about 50 meters, the communication signal is interrupted.
Editor through this experimental operation, found the following points
1 External antenna, the communication distance of the wireless module will be much longer
2 The external antenna, whether it is used for the transmitting module or the receiving module, the communication distance is basically the same
3 The external antenna can only be maximized if the transmitter and receiver modules are installed.
NiceRF, more than 10 years of focus on the development and production of low-power wireless modules, customer consultation is welcome.