当对信号进行采样时，为了避免信号混淆，选用的采样频率fs和被测信号最高频率fm应满足（）。 A: fs≥2×fm B: fs＝fm C: fs≤fm D: fs≤2×fm8
当对信号进行采样时，为了避免信号混淆，选用的采样频率fs和被测信号最高频率fm应满足（）。 A: fs≥2×fm B: fs＝fm C: fs≤fm D: fs≤2×fm8
Cars are mentioned in Paragraph 2 to show _____.
Cars are mentioned in Paragraph 2 to show _____.
设基带信号带宽为fm,则SSB信号的带宽为 A: fm B: 2fm C: fm/2 D: 4fm
设基带信号带宽为fm,则SSB信号的带宽为 A: fm B: 2fm C: fm/2 D: 4fm
鉴频时，应使2⊿fmax调频信号最大频偏的两倍2⊿fm
鉴频时，应使2⊿fmax调频信号最大频偏的两倍2⊿fm
through after 2)_____________ show the incidents of patients
through after 2)_____________ show the incidents of patients
对于FM波，当mf>>1时，B=2(mf+1)F≈2Δf，所以B近似
对于FM波，当mf>>1时，B=2(mf+1)F≈2Δf，所以B近似
有一个AM和FM波，载频均为1MHz，调制信号均为υΩ（t）=0.1sin（2π×103t）V。FM灵敏度为kf=1kHz/V，动态范围大于20V。（1）求AM波和FM波的信号带宽；（2）若υΩ（t）=20sin（2π×103t）V，重新计算AM波和FM波的带宽；（3）由此（1）、（2）可得出什么结论。
有一个AM和FM波，载频均为1MHz，调制信号均为υΩ（t）=0.1sin（2π×103t）V。FM灵敏度为kf=1kHz/V，动态范围大于20V。（1）求AM波和FM波的信号带宽；（2）若υΩ（t）=20sin（2π×103t）V，重新计算AM波和FM波的带宽；（3）由此（1）、（2）可得出什么结论。
Scorn in Pargraph 2 may exist in the following form
Scorn in Pargraph 2 may exist in the following form
The pricing (2) … are crucial, as it is vital to set out what form the price will take and when it will be (3) （2）为
The pricing (2) … are crucial, as it is vital to set out what form the price will take and when it will be (3) （2）为
2) They stood in line to buy tickets to the show for twenty minutes.
2) They stood in line to buy tickets to the show for twenty minutes.