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Lightning electromagnetic pulse (LEMP) is a severe threat to sensitive electronic devices installed in buildings. In order to protect these devices from LEMP effects, the evaluation of the electromagnetic fields inside the building is required. Numerous studies have been devoted to the analysis of these fields stemming from direct and indirect lightning strikes. In this paper, using a GPGPU-based,...
We propose an satellite observation to investigate preseismic lithosphere-atmosphere-ionosphere (LAI) coupling. Preliminary mission analysis shows that it is possible to prove not only a statistical correlation but also causation between earthquake and ionospheric anomaly even by three dedicated nano-satellites. The observation of proposed satellite constellation promotes a comprehensive understanding...
Several methods have been proposed for the calibration of an electrically small circular loop antenna in the MF and HF bands. They are the ‘standard field method,’ ‘three-antenna method,’ ‘impedance method,’ and so on. In this paper, the advantages and disadvantages of each method are discussed.
We are developing a data communication system for protection and disaster relief operations using TV White Space (TVWS) for a disaster rescue robot that works in a prohibited entry area. Such a secondary system operating in TVWS does not harmfully interfere with the primary system of the terrestrial digital broadcast service. The interference from the TVWS device should not exceed I/N of −10 dB in...
There has been increasing concern about the health effect of human body caused by the low frequency leakage field of household appliances. There are some commercial EM dosimeters for compliance test of ICNIRP guidelines, therefore it is possible to measure the reference level of exposure. In this study, we have calculated the exposure level using a magnetic field strength of around the IH cooker obtained...
In recent times, more than 60 percent of the world's energy is used to drive electric motors. Because of the growing requirements of speed control, pulse width modulated (PWM) inverters are widely used in adjustable speed drives. Noise generated by PWM inverter fed AC motor drive systems causes severe parasitic current problems, especially at the cases of high frequency. This paper proposes two new...
This paper describes critical EMC issues on the BepiColombo Spacecraft, the ESA mission to Mercury. EMC on this spacecraft is driven by a high power consuming electric propulsion system which can generate extremely high transient currents during operation, and the need for steerable high gain antennas for space to ground communication which can illuminate part of the spacecraft under certain link...
We propose a simple optical fiber link microwave measurement system that consist of a vector network analyzer, two modules of Electric signal to optical signal converter and a module of optical signal to electric signal converter. The system can measure S-parameters of two-port devices using a vector network analyzer (VNA) in full 2-port calibration. In this paper, we show frequency characteristics,...
Within the AIT-process the verification of magnetic cleanliness requirements is an essential pre-requisite to ensure mission success, especially for satellites with dedicated magnetic mission requirements e.g. SOLAR ORBITER. Magnetic cleanliness verification usually comprises a combination of analytical and experimental methods. During the “magnetic system test” the object to be tested is characterized...
To understand the characteristics of human electrostatic discharges (ESDs), using a 12-GHz digital oscilloscope, we measured discharge currents injected into an IEC (International Electrotechnical Commission) current calibration target through the fingertip from a human body charged at a voltage of 300 V. Occurrence frequencies of the current waveforms and their cumulative relative frequency distributions...
In this paper, we employed a two-step approach to evaluate the electromagnetic interference (EMI) voltage at cardiac pacemaker from human body communication (HBC) signals. In the first step, we calculated the input voltage of the analogue sensing circuit of pacemaker using an electromagnetic field analysis tool by considering the pacemaker as a receiving antenna. In the second step, we evaluated the...
There are many commercial shields for 3G and 4G mobile phones re-emerging onto the market, claiming specific absorption rate (SAR) reduction; however their effectiveness is questionable. In this paper, their SAR and induced electric field (E-field) are measured, and the corresponding induced E-field inside the human body with and without implanted medical devices is analyzed. Results have indicated...
We report on improvement of ESD characteristics of AlGaN/GaN high-electron mobility transistor (HEMT) using metal-insulator-metal (MIM) structure aluminium nitride (AlN) flip-chip (FC) submount. Compared with FC-free HEMT, measured results of the FC HEMT show the improvements of 25 and 150% under drain-to-source and gate-to-source electrostatic discharge (ESD) stress respectively, which is attributed...
AlGaN/GaN high electron mobility transistor (HEMT) was designed with improved surge protection characteristic through the use of a MSM-2DEG varactor connected in series to the gate of HEMT. Under an ESD surge stress of 1100 V or below, the HEMT incorporating this protection feature doesn't exhibit any change because the surge stress can be directly blocked by the MSM-2DEG varactor. Furthermore, flip-chip...
There are several standards that recommend the use of transmission line systems (TLS) as the field generation equipment for immunity testing. In general the assumption is that these systems provide a uniform field that will illuminate the whole vehicle under test. Additionally, It is commonly assumed that these systems do not radiate and that the shielded semi-anechoic chamber has no effect on their...
Overhead transmission lines generate electric and magnetic fields at power frequency. These fields play an important role in transmission line design and occupational safety standards compliance. Typically, the EMF exposure limits for electrical line design in Malaysia is based on established international or national standard of developed countries due to lack of local standard on EMF exposure limit...
This paper reports results of magnetic flux density (denoted as magnetic field hereafter) measurements under power transmission lines and around power distribution equipment. Measurements were carried out in accordance with IEC 62110 established in 2009, which prescribes measurement and evaluation procedures of uniform and non-uniform magnetic field generated by ac power systems with regard to human...
The common-mode current on AC cable is one of radiated disturbance source below 300 MHz. The method of using common-mode absorbing device (CMAD) is discussed to improve reproducibility of test result by stabilizing the termination impedance of AC cable. However, CMAD can't stabilize the differential-mode impedance because this acts as a kind of common-mode choke coil. In this paper, the influence...
At present, radiated emission measurement standards do not specify the common mode impedance for the outlet terminal of mains network to equipment under test (EUT) in the test site. Because of the difference in the terminating condition of EUT power cable which dominantly causes radiated emission in the frequency range between 30 MHz and 300 MHz, radiated emission measurements of a tabletop EUT are...
The Artificial Asymmetrical Network (AAN) defined in CISPR 16-1-2 Edition 1.2 (2006–08) is used primarily for the measurement of Common Mode (Asymmetric) conducted emissions on balanced telecommunications cables. In CISPR 22 (now CISPR 32), these AANs are referred to as Impedance Stabilization Networks (ISN). The AAN is intended to control several parameters when installed between the Equipment Under...
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