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功放参数中AM output的意思

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在看一个功放的datasheet，看到里面有个参数是AM output，请问这个参数是什么意思
AM output 15 %
DCSoutput = 0 to 32.0 dBm,
4% AM modulation at input
50 kHz modulation frequency

有没有人知道啊？

幅度调制呀。是幅度的变化量。

就是说如果输入的信号带有4%的调幅比例,那么经过PA后会变为15%,是表征PA线性度的一个指标.

Thereunder is explanation about the relationship between "AM modulation coefficient" & "dBc":AM modulation signal is denoted as:
[1+m*cos(Ws*t)]*cos(Wc*t)=cos(Wc*t)+(m/2)*cos[(Wc-Ws)*t]+(m/2)*cos[(Wc+Ws)*t]where,
m, is "AM modulation cofficient";
Ws, is "Signal phasic frequency";
Wc, is "Carrier phasic frequency".The power of carrier is Uc^2/r=1/r;
while the power of sideband is Us^2/r=(m/2)^2/r=m^2/(4*r).
So Sideband to carrier rate is 10*log{[m^2/(4*r)]/(1/r)}=10*log(m^2/4).so you can see when input, Sideband to carrier rate is 10*log(0.04^2/4)=-34dBc.after output, m=15%, Sideband to carrier rate is 10*log(0.15^2/4)=-22.5dBc.In your spec of PA, the AM/AM performance is tested under such condition:
15% AM modulation with fmod=50KHz that means -22.5dBc at 50KHz offset

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