Roman S. Surovtsev

Pulse decomposition in the turn of meander line as a new concept of protection against UWB pulses

Pulse decomposition in the turn of a meander line with the homogeneous dielectric filling is analyzed in detail. The study shows that the ultrashort pulse in the turn of a line with strong half-turn coupling is decomposed to subsequent pulses, having levels of 60, 60, -40, 20, -10%, when compared with a signal in the beginning of the turn. We obtained the conditions, providing decomposition of an ultrashort pulse into subsequent pulses. The research reveals the optimum value of capacitive coupling coefficient, being equal to 0.9, and providing the minimum level of pulses in the line end.

Simple method of protection against UWB pulses based on a turn of meander microstrip line

The possibility of protection against ultrawideband (UWB) pulses, based on the combination of distortions in a meander together and modal decomposition phenomena, is shown on the example of meander microstrip line. It is revealed that UWB pulse at the end of a line can be decomposed into a sequence of pulses of lower amplitude not exceeding 40% of the pulse level at the beginning of the line.

Possibility of Protection Against UWB Pulses Based on a Turn of a Meander Microstrip Line

Decomposition of an ultrawideband (UWB) pulse into a sequence of pulses with lower amplitudes in a turn of a meander microstrip line has been experimentally proved to be an effective method of protection against UWB pulses for electronic equipment. It has been shown that the output signal of the line can be minimized by means of equalization of amplitudes of the first three pulses. It has been achieved due to optimization of coupling between half-turns of the line. The obtained attenuation of a pulse with full-width-at-half-maximum of 40 ps is 6.3 times. Combination of experimental and simulation methods is used to obtain the results in time and frequency domains.

Delay line protecting against ultrashort pulses with increased duration

The paper shows the possibility to increase the duration of ultrashort pulse which can be decomposed in the one turn meander delay lines. For this purpose, we suggested a condition that increases duration of ultrashort pulse up to a value that is equal to twice the product of the minimum of per-unit-length delays of even and odd modes of a signal and the length of half-turns. Simulation showed the expansion of ultrashort pulses with increased duration when this condition is fulfilled. It has been revealed that such decomposition without proper optimization results in the increased amplitude of the output signal. Therefore, an additional optimization was made to provide additional reduction of the amplitude of ultrashort pulse resulting in 32% of input signal.

Influence of losses on ultrashort pulse decomposition in a turn of meander microstrip line

The paper analyzes influence of conductor and dielectric losses on the ultrashort pulse decomposition in a turn of meander microstrip line. The investigations revealed that losses in conductor have more significant influence on the amplitude and form of a pulsed signal than losses in dielectric. It is also shown that losses in conductor have more influence on the amplitude of odd mode pulse, while losses in dielectric have more influence on even mode pulse. However, complete consideration of losses has shown that losses significantly change only the odd mode pulse, while the crosstalk pulse and the even mode pulse are changed insignificantly. A noteworthy effect has been revealed: overlong fall of the second pulse (because of losses) is added to the third pulse and, thus, its amplitude is increased and delay is reduced. At last, it is shown that consideration of losses can reduce the optimum coupling between conductors by the criterion of minimal amplitude of the output signal.

Study of protective meander line turn with broad-side coupling

Protection of electronic equipment against ultrashort pulses by meander lines is considered. The results of cross-section parametric optimization and experimental investigations of a meander line turn with broad-side coupling are presented. As the result of the optimization, the set of parameters is obtained for the line per-unit-length modal delays difference maximization with the geometric mean of modes impedances of 50 Ohm. Based on the selected parameters the printed circuit board with meander delay line prototypes of different lengths is manufactured. Then the study of the prototypes in time and frequency domains was executed. The attenuation of the ultrashort pulse with the duration of 40 ps up to 4.2 times is experimentally obtained. It is revealed that the turn passband decreased from 715 to 365 MHz with the turn length increasing from 50 to 100 mm.

Parametric optimization of protective meander line turn in air filling by genetic algorithm

One-criterion parametric optimization by genetic algorithm (GA) of air protective meander line turn cross-section is executed. For this task the quality function which provides geometric mean of wave impedances for even and odd modes of the line (Z) to be equal to the 50 Ω is formulated. All of 4 cross-section parameters of the investigated structure are simultaneously optimized. The results of 5 GA runs with 10 and 100 generations of 30 individuals are described. Well reproducibility of Z value around the value of 50 Ω with deviation less than 0.1% is demonstrated. The optimization time costs were estimated. The source code of the program (in TALGAT software) is presented in Appendix.

Acceleration of multiple solution of a boundary value problem involving a linear algebraic system

Multiple solution of a boundary value problem that involves a linear algebraic system is considered. New approach to acceleration of the solution is proposed. The approach uses the structure of the linear system matrix. Particularly, location of entries in the right columns and low rows of the matrix, which undergo variation due to the computing in the range of parameters, is used to apply block LU decomposition. Application of the approach is considered on the example of multiple computing of the capacitance matrix by method of moments used in numerical electromagnetics. Expressions for analytic estimation of the acceleration are presented. Results of the numerical experiments for solution of 100 linear systems with matrix orders of 1000, 2000, 3000 and different relations of variated and constant entries of the matrix show that block LU decomposition can be effective for multiple solution of linear systems. The speed up compared to pointwise LU factorization increases (up to 15) for larger number and or...