NB module problem

QWE4562009

NB module problem [Copy link]

NB module problem

I am using Quectel BG95-M3 NB module. The transmission is slow now, the success rate is less than 50%, and the signal strength is only 10dbm. Due to product structure limitations, the antenna is made of FPC and can only be attached to the shell! The antenna factory is still debugging! Is there any way to improve the signal strength in the circuit?

Someone suggested to ensure that the RF circuit output is based on 50 ohm impedance! How to calculate the value of a resistor and two capacitors in the output π-type circuit?

Is there any other more effective method? Share it

ezezy

X1.X2.X3. Change the three resistors to 1.5K on both sides and 3.3 ohms in the middle. Try this π-type network. The attenuation is about 0.3-0.5dbm. The impedance is 50 ohms.

QWE4562009

ezezy posted on 2020-9-21 10:48 X1.X2.X3. Change the three resistors to 1.5K on both sides and 3.3 ohms in the middle of X1. Try this π-type network. The attenuation is about 0.3-0.5dbm. The impedance is 50 ohms

It's not appropriate to use resistors on both sides...

ezezy

QWE4562009 posted on 2020-9-22 18:31 It is not appropriate to use resistors on both sides. . .

No problem, I use it like this when I make a micro base station analog transmitter terminal connected to the antenna and LNA front end, but I have to connect a capacitor string at the end