Experimental study and SPICE simulation of CMOS digital circuits latch-up effects due to high power microwave interference are reported in this paper. As a traditional inherent destruction phenomenon, latch-up effect may jeopardize the correct function of the circuits, and could be triggered in various ways such as ESD pulse, cosmic ray, heavy ion particles etc. Through the directly injected experimental investigation of CMOS inverters, it is shown that the single short high power RF pulse not only could disturb and upset the inverters output logic voltage, but also might trigger CMOS latch-up effects. It is observed that the RF pulse leading to inverters latch-up effects have energy threshold characteristics, which means that the injected RF pulse power is inversely proportional to the pulse width. SPICE simulations indicated that the inverters maximum static consumption current in latch-up state will increase up to 6600 multiples compared to the normal value when input logic state is high. With the device scaling down, higher integration and higher working frequency, the power consumption problem plays a significant role, which makes CMOS logic circuits more vulnerable due to the latch-up effects under high power microwave threats.

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Experimental study and spice simulation of cmos inverters latch-up effects due to high power microwave interference

Reverberation chambers are widely used in electromag- netic compatibility test facilities because they provide a large working volume and are cheaper than other types of test facilities. In addition, they provide a statistically uniform fleld and generate a high maxi- mum electric fleld within a relatively large volume. The volume of the cavity, the structure of the stirrer, and high tested frequency must be used in the reverberation chamber appropriately. Changing a volume of cavity dimensions and test frequency can be di-cult in the rever- beration chamber because they were determined already in the design process. In these cases, the stirrer should be changed. We investigated of the efiects of various stirrer angles and heights on a reverberation chamber. The optimization of the stirrer with respect to various stirrer parameters was investigated; these parameters are related to fleld uni- formity, the quality factor, stirred e-ciency, and electric fleld polarity. Our results suggest that a reverberation chamber can be successfully operated if careful decisions are made regarding the stirrer design.

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Optimization of Stirrer with Various Parameters in Reverberation Chamber

Electromagnetic threat due to Intentional Electromagnetic Interference (IEMI) is shortly introduced at the beginning of this paper. High Power Microwave (HPM) as well as Ultra Wide Bandwidth (UWB) signals as a part of IEMI are described and compared with other electromagnetic threats. The main part of this paper is focused on data networks equipment and their electromagnetic immunity. Data networks are considered as a possible vulnerable part of infrastructures. HPM and UWB immunity testing of data networks is presented and discussed. Finally the most sensitive parts of data networks are discussed as well as relevant immunity comparisons.

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High Power Microwave effects on computer networks

The safety and reliability of electrical and electronic systems are questioned by exposure to electromagnetic environments, as they can suffer from errors, malfunctions and even permanent damage due to caused electromagnetic interference. In particular, cases in which the electromagnetic environment is originated with the intention to cause malfunctions or destructions in key electronic systems, like critical infrastructures, are in the focus of increasing public concern. The technological development of last decades resulted in a situation in which it became necessary to protect critical systems and infrastructure against intentional electromagnetic interference threats. In fact not all critical infrastructures might be vulnerable to such environments, but without a systematic risk assessment the current situation is unknown. The required level of confidence in the protection of electrical and electronic systems against electromagnetic interference can only be achieved by applying a systematic risk management process in all phases of the system lifecycle. This article provides an introduction to the electromagnetic interference risk management process as well as to the Threat Scenario, Effect and Criticality Analysis, a novel electromagnetic interference risk analysis methodology. In the second part of the article particular aspects of the electromagnetic interference risk analysis concerning the data structure of the electromagnetic interference threat scenario and resources available to a potential offender are discussed in detail.

A systematic approach for electromagnetic interference risk management

Standardization of High Power Electromagnetic (HPEM), environments, protection design and test methods is becoming increasingly important particularly as the perceived risk to society from HPEM is growing. Many generic standards and some application or product specific standards are now available. This letter will provide an overview of some recent developments in HPEM standards, in particular High Altitude Electromagnetic Pulse (HEMP) and Intentional Electromagnetic Interference (IEMI) phenomena.

Recent Developments in High Power EM (HPEM) Standards With Emphasis on High Altitude Electromagnetic Pulse (HEMP) and Intentional Electromagnetic Interference (IEMI)

This paper provides a summary of two susceptibility assessments conducted by the QinetiQ EMC group. The first assessment attempted to understand the susceptibility threshold of commercial off the shelf (COTS) computer equipment to a high power electromagnetic (HPEM), or high intensity radiated field (HIRF) environment. This environment was produced using the mode stirred reverberation chamber technique. The second assessment evaluated the susceptibility threshold of COTS computer network equipment to a high altitude electromagnetic pulse (HEMP) environment produced within the QinetiQ HEMP bounded wave simulator. These assessments have focused on the threshold of susceptibility of computer equipment and networks with variation in technology maturity. Technology trends are established where possible. The impact of EMC compliance on computer equipment immunity is also discussed. It is considered that the data presented in this paper will be informative to those seeking to protect systems and infrastructures from intentional and unintentional electromagnetic interference (EMI).

HPEM and HEMP susceptibility assessments of computer equipment

High-Power Electromagnetic (HPEM) environments can be considered to encompass lightning, Nuclear Electromagnetic Pulse (NEMP) and High-Power Radio Frequency (HPRF) phenomena including Directed Energy (DE) and Intentional Electromagnetic Interference (IEMI). HPEM environment definitions are now maturing and are now described in a variety of published standards. Methods to evaluate the effects on electronic systems and an understanding of effects mechanisms are perhaps less mature but this is a vibrant area of research. Due to a variety of factors described in this article protection and resilience of critical infrastructure from HPEM environments is becoming a pressing need.

Implications of high-power electromagnetic (HPEM) environments on electronics

Throughout the world there are plans to enhance the operation of electricity power networks to deal with the introduction of distributed and renewable power systems. The basic approach is to provide a new communications system to monitor and control future power networks (Smart Grid). Unfortunately electromagnetic disturbances such as those associated with typical electromagnetic interference (EMI) can cause problems with the operation of modern electronics. In addition a set of high power EM threats are of even greater concern, although the probability of occurrence for each threat is low. This paper introduces these three HPEM threats and describes the possible impacts on electronics within electricity networks of the future, if they are not protected before being placed in service.

An overview of the impacts of three high power electromagnetic (HPEM) threats on Smart Grids

The topic of Intentional Electromagnetic Interference (IEMI)1 has been studied for some time [1] yet the analysis of the risk posed to electronics rich infrastructure assets on which civilized society depends has not been fully evaluated and guidance on protection, whilst available [2], has not been widely implemented.

Richard Hoad

Papers

Recent Developments in High Power EM (HPEM) Standards With Emphasis on High Altitude Electromagnetic Pulse (HEMP) and Intentional Electromagnetic Interference (IEMI)

HPEM and HEMP susceptibility assessments of computer equipment

Implications of high-power electromagnetic (HPEM) environments on electronics

An overview of the impacts of three high power electromagnetic (HPEM) threats on Smart Grids

Overview of the European project ‘HIPOW’