Pavel E. Orlov

Improved design of modal filter for electronics protection

A new structure of modal filter which is more relevant for lightning protection of electronics than previously considered structures is proposed. Decrease of modal filter length or increase of original pulse width by factor of 10 and increase of modal filter attenuation from factor of 2 up to factor of 5 is shown. Condition for equal magnitudes of decomposed pulses and analytic formula for their values against a ratio of even to odd mode characteristic impedances are derived. Dependence of these values on coupling is shown for practical parameters of the new structure based on FR-4. On the basis of the calculated data an experimental prototype of an improved modal filter has been made. An experimental investigation has been performed.

New concept of critical infrastructure strengthening

Strengthening of critical infrastructure is considered. Modal reservation of electronics is proposed as a new concept of the strengthening. The concept combines a widely used cold backup and a recently proposed modal filtration. It makes electronics reliable as well as protected against electromagnetic interference, especially the ultra-wide band pulses. New printed circuit board structure is suggested for implementation of the proposed concept. Results of simulation in time and frequency domains are presented for the suggested structures. Considerable attenuation of dangerous excitations shows that the new concept and structure are promising.

Evaluation of efficiency of modal filtration in different types of redundant electrical connections

Electrical connections of control and communication systems are considered. We have computed electrophysical parameters for the considered types of coupled electrical connections in a wide range of parameters applied in practice. If we take into account real length of interconnections, duration of an interfering pulse go up to 37 ps for integrated circuits (IC), 6 ns for printed circuit boards (PCBs) and 19 ns for flat cable, attenuation coefficient for an interfering pulse is 2.1…2.8 times. Range of frequencies that assure the maximum attenuation of an interfering pulse for IC is higher than 13 GHz, for PCB it is higher than 143 MHz, for FFC it is 26.240 MHz. These results prove efficiency of modal filtration in different types of redundant electrical connections of communication and control systems.

Comparative Electromagnetic and Quasi–Static Simulations of a Shortpulse Propagation along Microstrip Meander Delay Lines with Design Constraints

Abstract A numerical analysis of microstrip meander delay lines is considered. Results of quasi-static and electromagnetic simulations are given. It is shown that when increasing a number of turns and proportionally reducing their length, distortions of a pulse signal in the line are reduced. At the same time, despite structure’s electrical width increase, the agreement between the results of quasi-static and electromagnetic analyses is improved. Thus, it is demonstrated that when designing the microstrip meander delay lines with minimal distortions, the quasi-static analysis is relevant.

Quasistatic and electromagnetic simulation of interconnects of printed circuit boards with modal reservation

Quasistatic and electromagnetic simulation of three cross-sections of interconnects of new PCBs for circuits with redundancy is performed. It is shown that the results are consistent. The relative difference was 4% for the difference of per-unit-length delays of modes and 40% for the pulse amplitudes. Meanwhile, the simulation time of quasistatic analysis is 263–1261 times less than that of electromagnetic analysis.

Method of lay-out of multilayer PCBs for circuits with redundancy

A new method of lay-out of multilayer printed circuit boards for circuits with redundancy is considered. A structure with two conductors is considered; in this structure the initial interference pulse is decomposed into two pulses with fourfold lower amplitudes. The paper demonstrates the effect of the relative dielectric constant value of the sublayer between redundant and backup conductors on difference between per-unit-length delays of even and odd modes. The difference can change a sign and multiply the absolute value. Furthermore, increase of coupling between conductors decreases the amplitude of the output signal. The obtained results prove that the proposed method allows to increase interference immunity of the redundant circuits in multilayer printed circuit boards.

New results on EMC simulation for space projects of TUSUR University

The paper presents and summarizes theoretical and practical results of the UEM-TUSUR project which is focused on the development of approaches, technologies and software for EMC simulation of unified electronic modules of spaceborne equipment. Theoretical and practical results for quasi-static and electromagnetic analysis, solution of linear algebraic systems and modal filtration are presented briefly. Outlook for applications of the obtained results in the current SAN project is given.

Analysis of power dissipation in resistive terminations of single- and multistage modal filters

A new approach to the protection of electronics is considered to comply better with the requirements of lightning protection. Input power distribution in modal filter (MF) resistive terminations is analyzed. Dependencies of the MF power dissipation on the excitation pulse parameters have been obtained for 1-, 2-, 3-, 4-stage MF with fixed total length. Conclusions reveal potentially vulnerable parts which should be improved in order to prevent the MF failure due to overload of certain parts.

Contactless Modal Phenomena Based Approach to Detecting, Identifying, and Diagnosing of Electrical Connections

This paper presents a unified description of a new approach for contactless detection, identification, and diagnostics of electrical connections and describes an idea and principles of using modal probing for these tasks. Simulation and experimental results on pulsed signal propagation through flat cables demonstrate the modal decomposition of a pulsed signal, which varies depending on the state of the probed wire. It is shown that the presented tasks can be solved by modal probing. The article also considers the analysis of modal distortions in frequency domain and gives the formula for its practical use. This formula can be useful when the pulse duration time is longer than the minimum of mode delay difference. In conclusion, we present further development ideas of the modal probing.

Method of lay-out of a multilayer PCB for circuits with triple reservation

A new method of lay-out of a multilayer PCB for circuits with triple reservation is considered. Simulation of four-conductor structure is performed. In this structure UWB pulse decomposed to 4 pulses with smaller amplitudes. These results demonstrate that the proposed method allows to increase interference immunity of PCB circuits with triple reservation.