The characteristic loss of MMDS signals propagation in route is demonstrated. From the aspect of engineering and technology needs,the analysis of parameter design of the MMDS receiving and transmitting system are conducted,and the measure of anti interferrence are given.

The advanced model of power transformer winding based on PD signals propagation is put forward for the first time. Through theoretical calculation and simulation analysis for transformer winding brand-new model, the relations between winding frequency characteristics and winding parameters are discussed.

This paper we first bring the concept of “quantitative acupuncture”, study itsfunction on physiological modulation, model the electrical signals propagation systemin biology, physics and mathematics.

METHODS Combining the theory of propagation in the lossy layered media with the technology of computer simulation, the propagation characteristic was analyzed and compared, through which the vital signals propagation characteristic in layered media was analyzed.

Therefore, the following fundamental studies should be executed: characteristics of discharge pulse signals, propagation performance of discharge pulse signal along the windings, suppression techniques against the strong on-site electromagnetic noise, discharge pattern recognition and fault diagnosis.

It models realistically users motion, and radio signals propagation in a city-like scenario.

The sound (tone signals) propagation is studied on a 510-m-long constant-depth (38 m) track (TON-310 Hz) and a 10.6-km-long track (TON-320 Hz), which is set up by placing the self-contained transmitter at the bottom (at a depth of 65 m).

Both backplanes have been successfully manufactured and tested, after careful pre-layout simulation of the signals propagation and integrity.

The relation between three main factors (waveform, channel and receiver) of active sonar is discussed in this paper. The models of active sonar channel, which include marine reverberation, signal propagation and object scattering in sonar processes, are described, by generalized scattering function and generalized coherence function. Physical significance and measuring method of both function are explained with aid of channel output corralation function and matched filter output. Finally, the fundamental...

The relation between three main factors (waveform, channel and receiver) of active sonar is discussed in this paper. The models of active sonar channel, which include marine reverberation, signal propagation and object scattering in sonar processes, are described, by generalized scattering function and generalized coherence function. Physical significance and measuring method of both function are explained with aid of channel output corralation function and matched filter output. Finally, the fundamental principles for design of the optimum waveform and the optimum receiver are presented.

The theory of electromagnetic wave propagation on multiconductor overhead lines presented in this paper mainly deals with the study of propagation of power line carrier,and other low and high frequency signals on power lines. It is an important part of the theory of electromagnetic wave propagation. The mathematical model for calculating propaga- tion characteristics of a line can be derived. In this paper, a general solution to the electromagnetic field equations of signals propagation along a line is...

The theory of electromagnetic wave propagation on multiconductor overhead lines presented in this paper mainly deals with the study of propagation of power line carrier,and other low and high frequency signals on power lines. It is an important part of the theory of electromagnetic wave propagation. The mathematical model for calculating propaga- tion characteristics of a line can be derived. In this paper, a general solution to the electromagnetic field equations of signals propagation along a line is obtained by using a more strict method.Carson's method as well as some other methods are also discussed.We first consider a z directed infinite horizontal wire located at (xc,yc)abovethe multilayer earth,as shown in Fig.1. The current in the conductor is assumed to have the form I = I0e-rz. According to the theory of electromagnetic fields,the six components of the total electromagnetic fields in any one of the" regions can be expressed by eq. (8),in terms of two vector potentials A and F. The fields on every interface surface of these potentials satisfy the continuity constraints of eq.(9).Therefore the z component of the electric field above the ground is obtained in eq.(10). In a multiconductor system, the electromagnetic-fields in any region are the summation of the fields produceed by currents in every conductor.The solution to the axial component Ezo above the one-layer earth is obtained in eq.(24).In the derivation above, the only approximation made is that the wire is thin, i.e. rc< yc. Carson in his paper made two other approximations, eqs. (27)and(30).If these approximations are applied to eq.(24), we can obtain Carson's formula(31). In this case a multiconductor line above the earth can be treated as a transmission line.Inother methods,fewer approximations and two-or three-layer earth are assumed, so that the results obtained are more precise than those by Carson's formula, but they are more complicated, and therefore Carson's formula is still more populary used.Under conditions of very high frequency and extraordinary earth condition and line construction, there will be serious errors in Carson's formula, and the other formulas have also limited application. The method presented in this paper is generally applicable.

In this paper, the model theory used to solve line transmission equations is introduced, and a new algorithm, called "Incident and Reflected Wave Method", is presented.If the model transformations V = SVm and I = QIm are applied, we can obtain eqs.(12)and (13).Then the solution's of phase voltages and currents can be calculated. The model theory is used not only to resolve the transmission eqs., but also to explain the phenomenon of signal propagation on a line and make some simplified calculations.The...

In this paper, the model theory used to solve line transmission equations is introduced, and a new algorithm, called "Incident and Reflected Wave Method", is presented.If the model transformations V = SVm and I = QIm are applied, we can obtain eqs.(12)and (13).Then the solution's of phase voltages and currents can be calculated. The model theory is used not only to resolve the transmission eqs., but also to explain the phenomenon of signal propagation on a line and make some simplified calculations.The advantages of this algorithm are implicit computation, less difference in absolute values between the components in the parameter matrix. Also it does not restrict. impedance at nonhomogeneous' points or on nonhomogeneous kinds of lines. Therefore numerical calculations are very accurate. The flow chart of the computer program based on this algorithm is shown in Fig.2. It can be used not only on minicomputers but also on some microcomputers.Some calculated results obtained by a superminicomputer are shown in Tables 1& 3 in comparison with the results calculated by some foreign supplier and values obtained by measurement on the sites.