请教功放参数中AM output的意思

no8

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

no8

有没有人知道啊？

bestdesign

幅度调制呀。是幅度的变化量。

hata_sang

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.

nextmobile

<P>Thereunder is explanation about the relationship between "AM modulation coefficient" &amp; "dBc":</P><P>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]</P><P>where,
m, is "AM modulation cofficient";
Ws, is "Signal phasic frequency";
Wc, is "Carrier phasic frequency".</P><P>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).</P><P>so you can see when input, Sideband to carrier rate is 10*log(0.04^2/4)=-34dBc.</P><P>after output, m=15%, Sideband to carrier rate is 10*log(0.15^2/4)=-22.5dBc.</P><P>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</P>[br]<p align=right><font color=red>+5 RD币</font></p>