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根本潇洒



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紧急求助:英语强人帮忙翻译,是英语群一个jj叫帮忙的。

An AM broadcast station has a peak carrier voltage of 1.5 kV. The modulating signal frequency
is 10 kHz and the carrier frequency is 1500 kHz. The depth of modulation is 35%. Compute the
following:

The upper and lower sideband frequencies.
The peak modulating signal voltage.
The peak upper and lower sideband voltages.
The maximum value of the AM wave.
4.    A spectrum analyser with an input impedance of 50 ohm is used to measure the power spectrum
of an AM signal obtained by modulating a carrier with a sine wave. The carrier power is 1 W,
and the upper and lower side frequencies have a power of 330 mW each. Determine,
the total power of the AM wave.
the peak carrier voltage.
the percentage modulation.
the peak voltage of modulating sine wave.
peak voltage of the upper and lower side bands.
5.    An AM transmitter has a carrier power level of 50 kW. When it is transmitting a test tone (sine
wave), compute the following:
The total transmitted power when the modulation depth is 50%.
The power in each sideband (with a modulation depth of 50%).
The total transmitted power when the depth of modulation is 100%.
The pow4r in each sideband (with a modulation depth of 100%).
6.    An envelope detector is designed such that its RC time constant is equal to the period of the
modulating signal. Assuming that AM broadcast band extends from 540 kHz to 1600 kHz, and
that the highest modulating signal allowed is 10 kHz, determine the value of C given that the
load presented to the preceding stage must be at least 10


顶端 Posted: 2006-10-14 21:30 | [楼 主]
fksz23



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4一个输入阻抗为50欧的频普分析仪被用来则量一个AM信号的功率谱,AM信号是由一个载波为正旋波的信号调制来的,载波信号能量为1W,上下边频各有330 mW的能量
判断:
AM波的总能量,峰值电压,调制度
调制正旋波的峰值电压,上下边带的峰值电压


[ 此贴被fksz23在2006-10-14 22:18重新编辑 ]
顶端 Posted: 2006-10-14 22:09 | [1 楼]
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6一个包洛检波器被设计成RC时间常数等于调制周期
假定AM广播信号带宽为540KHZ-----1600KHZ,同时最高调制
信号频率为10KZ
决定C值
假定........(呵呵,不会了哈)
Load是负载
不知道preceding stage是什么,好象是上升时间??
好象是假定上升时间至少为10,不过不确定哈
顶端 Posted: 2006-10-14 22:18 | [2 楼]
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5载波功率为50KW的AM波发射机,当发射一个正弦波时
计算
当调制深度为50%时,总发射功率是多少,每个边带功率是多少
当调制度为100%时,总发射功率功率为多少,每个边带功率是多少?
顶端 Posted: 2006-10-14 22:22 | [3 楼]
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