第一节电磁波的基本知识 1、参数 周期T、频率f、速度v、波长入、相位φ及其相互关系:T=1/f, =T.v, 9=27 ft. 2、电磁波普 （1)全普与窗口 （2)卫星大地测量常用普

1 At a frequency of 796 Hz, compute Zo,u and for a line having the following parameters: F2230 u H/km,=0.0055 u F, r-6./km, g negligible. 2 At certain frequency, transmission line has Zo=5560°andy=0.005+j0.03np/km The line is 60 km long. A sinusoidal voltage of 100V at the specified frequency is applied to one end. Find:

1 Find F(s) if f(t) = (a)(t-3);(b)4t u(t-3); (c)4 cos to(t-3). 2 Obtain partial-fraction expansions for each of the following rational functions, and find the corresponding time functions:

一、描述连续系统的微分方程如下,写出各系统的状态方程和输出方程。 (1)y(t)+5y2(t)+7y(t)+3y(t)=f(t) (2)y2(t)+4y(t)=f(t) 二、描述连续系统的系统函数如下,画出其直接形式的信号流图,写出其相应的状态方程和输出方程

Any periodic waveform f(t)f(t) can be expressed by a Fourier series provided that (1) If it is discontinuous, there are only a finite number of discontinuous in the period T (2)It has a finite average value over the period T (3)It has a finite number of positive and negative maximums in the period T

ad prep.(后+acc.)到近于 albus,adj.A.白色的 alternatius,adj.A.互生的 annus,ad.a.一年生的 anthera,s.f.I.花药 arbor,s.f.II.乔木树木 aureus,adj.a.金黄色的

University of California,Davis 69.1 Modulation and Demodulation Jefferson F. Lindsey III Modulation. Superheterodyne Technique. Pulse-Code Southern Illinois University at Modulation. Frequency-Shift Keying. M-ary Phase-Shift Carbondale Keying. Quadrature Amplitude Modulation Dennis F. Doelitzsch 69.2 Radio 3-D Communications Standard Broadcasting (Amplitude Modulation).Frequency

Non-Inertial Reference Frame Gravitational attraction The Law of Universal Attraction was already introduced in lecture D1. The law postulates that the force of attraction between any two particles, of masses M and m, respectively, has a magnitude, F, given by F= (1) where r is the distance between the two particles, and G is the universal constant of gravitation. The value of G is empirically determined to be

In this lecture we will consider the equations that result from integrating Newtons second law, F=ma, in time. This will lead to the principle of linear impulse and momentum. This principle is very useful when solving problems in which we are interested in determining the global effect of a force acting on a particle over a time interval Linear momentum We consider the curvilinear motion of a particle of mass, m, under the influence of a force F. Assuming that

We have seen that the work done by a force F on a particle is given by dw =. dr. If the work done by F, when the particle moves from any position TI to any position T2, can be expressed as, W12=fdr=-(V(r2)-V(1)=V-v2, (1) then we say that the force is conservative. In the above expression, the scalar