例 6-1 已知载波频率 f c =100MHz, 载波电压幅度 U cm =5V ,调制信号 U Ω (t)=cos2π × 10 3 t ,写出调频波的数学表达式(设这个调制信号的最大频偏 Δf max 均为 20kHz )
A.
5cos(2π×10 8 t+10sin2π×10 3 t)
B.
5cos(2π×10 8 t+20sin2π×10 3 t)
C.
5cos(2π×10 8 t+30sin2π×10 3 t)
D.
5cos(2π×10 8 t+40sin2π×10 3 t)
拍照语音搜题,微信中搜索"皮皮学"使用
参考答案:
参考解析:
知识点:
皮皮学刷刷变学霸
举一反三
【简答题】Answer the questions in spoken English. (音频时长不短于2分钟) What is your understanding of the so-called “first-tier universities”? Can you name some of the famous universities in the world?
【简答题】Practice the following situation, using some of the expressions provided above. Situation: Suppose you are a salesperson working in a small computer company. You are expected to sell 1,000 desktop com...
【单选题】Most of the big sites and some of the little sites allow you ______ a user name and password so that you can enter the site and ______ your account.
【简答题】You can see Pizza Hut(必胜客) every some blocks, so it must be a very big business. Indeed it is. But believe it or not, the business was started in 1958 by two college students with a loan of 600 dollar...