Comparison of different performances of wireless modules

　　As we all know, wireless modules have two common performances. The following small series with outstanding skills will introduce the comparison of the two performances.As can be seen from the new data, radio Module The market influence is also growing, and the product share is also relatively increasing, which has great potential in the future. https://www.hkulike.com/

　　

　　Firstly, the instantaneous frequency of the FM carrier transmitted by the FM transmitter is that the FM wave that changes with the modulation signal is an equal amplitude wave, and its maximum power is equal to the average power; The amplitude modulation transmitter emits an amplitude signal, and the maximum transmission power is equal to 4 times the average power. If the last stages of AM transmitter and FM transmitter use the same type of power tubes, and both are estimated according to the maximum power, the power emitted by FM transmitter is four times the average power emitted by FM transmitter.

　　

　　The main feature of FM is its strong anti-jamming performance. The so-called strong anti-jamming performance mainly means that the signal-to-noise ratio at the output of FM receiver is greater than the signal-to-noise ratio at the output of FM receiver under the same input signal-to-noise ratio.

　　

　　The reason why FM has stronger anti-jamming ability than AM can be analyzed from the power of the transmitted signals of the two systems. The power of the side frequency component of FM wave is divided from the carrier power. Its sidebands are not only numerous, but also increase in amplitude, which means that the proportion of power converted into sidebands in carrier rate is large, and the maximum power of sidebands of amplitude-modulated waves is equal to that of carrier power. Therefore, FM has more side frequency power than AM, which means it is more capable of overcoming the noise and interference in the channel or the machine.

　　

　　Secondly, we can make a comparative analysis from the mediation of receiving signals. Because the information of amplitude modulation signal is contained in the amplitude of the amplitude modulated signal, the demodulated envelope detector can’t suppress the parasitic amplitude modulation interference, while the information of FM signal contains the frequency change at the moment of high frequency oscillation, so the parasitic amplitude modulation caused by interference can be removed by limiter.

　　

　　Therefore, the anti-interference performance of FM system is better than that of AM system, regardless of the sideband power of the transmitted signal or the demodulation of the received signal.