Sensitive information can have its security compromised by unintentional electromagnetic emissions from the information technology equipment (ITE) being used to process it. It is important to assess the likelihood of a potential compromise, and this requires radio frequency (RF) engineering expertise to predict the likelihood of the vulnerability occurring. This paper describes the development of a fuzzy inference system that can be used to assess the radiated and conducted vulnerability likelihood of unintentional electromagnetic emanations. The system has the potential to be a valuable tool for cybersecurity practitioners without RF expertise. The system has been tested on office-based ITE devices, and it is effective in predicting the likelihood of radiated and conducted vulnerabilities occurring. Areas of future work include extending the fuzzy inference system to use RF propagation models and enabling it to make vulnerability likelihood predictions after countermeasures have been applied.

The purpose of this study was to model the relationships between the vulnerability factors that relate to unintentional compromising electromagnetic emanations from Information Technology Equipment (ITE). ITE vulnerabilities of this type can occur in many contexts including office and manufacturing environments using for example thin client and laptop technologies. The study applies a Causal Loop Analysis to the vulnerability factors to show the inter-relationships between them. This enables a clearer understanding of their relative significance when assessing vulnerability likelihood. The resulting causal loop analysis will be used in future work to develop a decision support tool for cyber security practitioners, when assessing the likelihood of unintentional emanations from ITE leading to the compromise of sensitive information.

The purpose of this study was to capture through a systematic literature review the domain specific knowledge related to unintentional compromising electromagnetic emanations from Information Technology equipment. It applies a qualitative thematic analysis to the identified papers to show the main themes and then uses concept mapping to organise and represent the acquired knowledge. The resulting concept map will be used in future work to develop a list of factors that Radio Frequency Engineers use to assess the likelihood of unintentional emanations leading to the compromise of sensitive information.

Information technology equipment (ITE) processing sensitive information can have its security compromised by unintentional electromagnetic radiation. Appropriately assessing likelihood of a potential compromise relies on radio frequency (RF) engineering expertise-specifically, requiring knowledge of the associated causal factors and their interrelationships. Several factors that can cause unintentional electromagnetic emanations that can lead to the compromise of ITE have been found in the literature. This paper confirms the list of causal factors reported in previous work, categorizes the factors as belonging to threat, vulnerability, or impact, and develops an interpretive structural model of the vulnerability factors. A participatory modelling approach was used consisting of focus groups of RF engineers. The resulting hierarchical structural model shows the relationships between factors and illustrates their relative significance. The paper concludes that the resulting model can motivate a deeper understanding of the structural relationship of the factors that can be incorporated in the RF engineers' assessment process. Areas of future work are suggested.

Most existing radio frequency (RF) spectrum analyzers use conventional superheterodyne architecture to remove images associated with the down conversion of RF input frequency to some intermediate frequency (IF) for further processing, and their complexity increases as the frequency range of interest is extended. This article describes a novel digital system architecture for spectrum analyzers based on quadrature down conversion. Quadrature down conversion architectures where image responses are inherently rejected are normally used to analyze a single frequency or a very narrow frequency spectrum. This article proposes using quadrature architecture in an ultrawideband spectrum analysis application. A wideband spectrum analyzer receiver with compensation for gain and phase imbalances in the RF input range, as well as compensation for gain and phase imbalances within the IF passband complete with resolution bandwidth (RBW) filtering, video bandwidth (VBW) filtering, and amplitude detection, is implemented in a low-cost field-programmable gate arrays (FPGAs). The proposed method still achieves the desired image rejection performance specification, is power-efficient, and significantly simplifies the RF front-end hardware in comparison to state-of-the-art methods.

The study explores the influencing factors that Radio Frequency (RF) Engineers take into consideration when assessing the likelihood of unintentional electromagnetic radiation compromising the security of Information Technology Equipment. A focus group research methodology is adopted, and the results analyzed using a cause-and-effect technique. Two focus groups of RF Engineers identified twenty-six influencing factors they considered when assessing likelihood. Through the cause-and-effect technique it was possible to categorize the factors in terms of threat, vulnerability, and impact (the three constituents of a qualitative risk calculation). This information can be used by cyber security practitioners with little or no RF experience to provide a better understanding of the significance RF Engineers place on specific factors particularly when assessing vulnerability likelihood.

This paper reviews recent developments in automatic impedance matching and antenna tuning for wireless and mobile communications. UHF Tunable Matching Network (TMN) topologies are considered together with electronic device technologies for tuning a TMN and automatic tuning algorithms. Integrated Power Amplifier (PA) matching/antenna tuning, downlink (receive only) antenna tuning and antenna tuning for Multiple Input Multiple Output (MIMO) are also included.

This paper reviews recent developments in design of antennas and impedance matching networks for RF Energy Harvesting (RF-EH) at UHF. The antenna design is considered in conjunction with the requirements that it places on the impedance matching network (IMN), in order to match the load which is an RF to DC converter. It is shown that there may be advantages in using an interface impedance between the antenna and the IMN that differs from the conventional 50 Ω impedance. Various options are considered for the design of an IMN driving a rectifier load. A novel adaptive IMN architecture is proposed that can match two different load impedances, depending on the received power level. This can optimize Power Conversion Efficiency (PCE) over a range of different input powers that may be encountered in RF EH.

An adaptive broadband antenna tuning technique using quantum genetic algorithms is proposed in this paper. This method is fast and can achieve a global optimal solution. It is useful for software defined radio systems using a single antenna for multiple mobile and wireless bands. Simulations have been conducted using GSM, UMTS and both standards, with different antenna impedances. The frequency band of the dual standards ranges from 1.7 to 2.2GHz. Simulation results show good accuracy of the proposed tuning technique.

In this study an adaptive impedance tuning scheme based on the quantum genetic algorithm (QGA) is proposed. A low-pass passive LC impedance matching network is used and tuned by a QGA controller. The tuning algorithm iterates until the matching point is reached. Simulations and results of the QGA tuning method are presented for 1.8 and 2.4 GHz of mobile and wireless communications with different antenna impedances. Comparison of the proposed QGA tuning method with conventional genetic algorithm-based tuning method is also given, which shows that the QGA tuning algorithm is much faster. The proposed QGA method can also be used for tuning a radiofrequency band by tuning the impedance matching network to the band centre frequency. Simulation results for the universal mobile telecommunications system band of 60 MHz width and Industrial, Scientific and Medical band of 200 MHz width all show good performances.

A novel Fractal planar inverted F antenna F-PIFA based on the self affinity design is presented in this paper. The procedure for designing a Fractal Planar Inverted F Antenna is explained and the 2 nd iteration of Sierpinski Carpet is chosen as an antenna for mobile phones. The F-PIFA has a total dimension of 27 mm × 27 mm and is designed and optimized to receive GSM (Global System for Mobile Communication) and UMTS (Universal Mobile Telecommunication System) and HiperLAN (High Performance Radio LAN). The frequency ranges are from 1900 MHz to 2100 MHz, 1885 to 2200 MHz for 3G and 4800 MHz to 5800 MHz for HiperLAN respectively. The antenna covered the GSM, UMTS and HiperLan frequency ranges with -6dB return loss and has an almost omni-directional radiation pattern. This antenna has been tested using a mobile phone model and the performance met all the criteria for a mobile phone application.

This paper describes the design of an antenna reflection coefficient measurement system. The prototype measures the real and imaginary components of the reflection coefficient (/spl rho/) in the frequency range 1.8 MHz-30 MHz. The system is able to operate with high level ambient signals present at the antenna feed point, whilst maximum measuring signal power delivered to the antenna is limited to 1 /spl mu/W. An experimental evaluation of the prototype is described. The measurement error is equivalent to less than 5% in magnitude |/spl rho/|, and 4/spl deg/ in phase