The Experts below are selected from a list of 294 Experts worldwide ranked by ideXlab platform

K. Ram Prakash - One of the best experts on this subject based on the ideXlab platform.

  • Control of electromagnetic waves through electromagnetic shielding
    2011 International Conference on Emerging Trends in Electrical and Computer Technology, 2011
    Co-Authors: G. Sindura, K. Ram Prakash, Peedikakkandy Salil
    Abstract:

    In this paper, propagation of electromagnetic waves around the Shielded Enclosure is analyzed through simulation using MATLAB. Also the importance of electromagnetic shielding and the effect of aperture in Shielded Enclosure are revealed using MATLAB. All electronic equipments emit electromagnetic waves during operation. It can be controlled through electromagnetic shielding. For the equipments to operate well in an electronic environment all equipments are Shielded. Electromagnetic shielding also reduces the hazardous effect to human lives. The most difficult problem in the design of Shielded Enclosure is the presence of apertures. Apertures are included for input/output connection, ventilation, trigger, etc.

  • Modeling and Study of Shielding Effectiveness of Shielded Enclosure and PCB and its Effect due to Loading Effect
    Wireless Communication, 2011
    Co-Authors: G. Sindura, Peedikakkandy Salil, K. Ram Prakash
    Abstract:

    In this paper (i) shielding effectiveness of Shielded Enclosure with single and multiple apertures (ii) Radiation from PCB without shield (iii) Radiation from PCB with shield are analyzed using computational electromagnetic software tool-FEKO. Electromagnetic shielding involves shielding components from electric and magnetic fields and also preventing electronic devices from sending them out. In order to achieve electromagnetic compatibility, mainly with respect to radiated emission and radiated immunity it is required to have a good shielding effectiveness for the equipment Enclosure. Shielding Effectiveness is defined as the ratio of the input field of the unShielded load to that of the Shielded one. The Shielded Enclosure is modelled with both single and multiple apertures. The shielding effectiveness of both Enclosures are found. The PCB is modelled with a ground plane at the bottom and a trace at the top. Then the radiations from PCB are analyzed, before and after the shield. The height of the PCB which is kept inside the Enclosure is varied to find the variations in radiation.

Valter Mariani Primiani - One of the best experts on this subject based on the ideXlab platform.

  • ESD field penetration through slots into Shielded Enclosures: a time domain approach
    IEEE Transactions on Electromagnetic Compatibility, 1997
    Co-Authors: Graziano Cerri, R. De Leo, R. De Rentiis, Valter Mariani Primiani
    Abstract:

    This paper presents a time domain approach for the analysis of the coupling between an electrostatic discharge (ESD) current and the internal region of a Shielded Enclosure with a slot. The application of the equivalence principle allows us to obtain an integro-differential equation for the unknown distribution of the aperture electric field. The numerical solution is obtained by an iterative procedure developed by the method of moments (MoM) in the time domain. The approach is also applied at the case of a transient incident field of a plane wave impinging on the Enclosure. The use of proper impulse responses for the space and cavity regions make the model efficient from a computational point of view, without loss in accuracy. Theoretical results are validated by measurements.

  • theoretical and experimental evaluation of the electromagnetic radiation from apertures in Shielded Enclosure
    IEEE Transactions on Electromagnetic Compatibility, 1992
    Co-Authors: G Cerri, Valter Mariani Primiani
    Abstract:

    The problem of the radiated emission from apertures in metallic Enclosures has been theoretically and experimentally investigated. In particular, the tangential electric field in the aperture has been evaluated by two methods: the first is helpful during the design stage and the second during the prototype development stage of electronic equipment Shielded by a metallic box. The first method is a rigorous approach and uses the equivalence principle that leads to an integral equation then solved by the method of moments. The second is an approximate technique. This technique is based on simple, cheap, and quick measurements of the normal components of the magnetic field across the aperture. Numerical simulation in good agreement with experimental results is shown. >

Gert Frølund Pedersen - One of the best experts on this subject based on the ideXlab platform.

  • Over-the-Air Testing for Carrier Aggregation Enabled MIMO Terminals Using Radiated Two-Stage Method
    IEEE Access, 2018
    Co-Authors: Huaqiang Gao, Weimin Wang, Wei Fan, Yuanan Liu, Gert Frølund Pedersen
    Abstract:

    Multiple-input multiple-output (MIMO) over-the-air (OTA) testing of wireless devices has become increasingly attractive in radiated performance evaluation. As one of the OTA testing methods, the radiated two-stage (RTS) method achieves flexible channel models with low-system cost. However, the existing MIMO OTA testing using RTS method is valid only for single carrier frequency application. This paper applies the RTS method to multiple carrier frequency applications [carrier aggregation (CA)]. Two setups are presented to discuss system cost and calibration time. To validate the RTS OTA testing for CA, the transfer matrices from the OTA antenna ports to device under test antenna ports in three types of RF Shielded Enclosure are investigated. The results demonstrate that the applied RTS method for CA works better in anechoic chambers. One calibration matrix might need to be adopted for each component carrier when the frequency separation of component carriers is large.

Yukio Yamanaka - One of the best experts on this subject based on the ideXlab platform.

  • EVALUATION OF E-FIELD UNIFORMITY FOR IMMUNITY TESTING IN A REVERBERATION CHAMBER
    2000
    Co-Authors: Katsushige Harima, Yukio Yamanaka
    Abstract:

    Testing for immunity against electromagnetic disturbances has become an important aspect of preventing malfunctions in electronic equipment, particularly medical equipment, caused by mobile and other radio transmitters. Radiated immunity tests are generally performed in an anechoic chamber as a standard method [1]. However, reverberation chamber and TEM waveguides, such as a stripline and a TEM-cell, are discussed with IEC and CISPR as an alternative or new testing to conventional measurement, which uses an anechoic chamber [2]-[4]. The reverberation chamber is a Shielded Enclosure equipped with one or more mechanical stirrers [5]-[8]. The stirrers are used to vary the electromagnetic boundary conditions to obtain a statistically uniform field in the chamber. Therefore, the field in a reverberation chamber, in which the direction of polarization changes randomly by the stirrers, is different from that of an anechoic chamber. Determining the number of stirrer positions and measurement locations for a given test volume in a reverberation chamber is important because they affect the uniformity and field calibration of the test volume. We have experimentally evaluated the effect on field uniformity of the number of stirrers, their positions, and the number of locations measured for the case of a reverberation chamber applied to radiated immunity testing.

  • EVALUATION OF E-FIELD UNIFORMITY FOR IMMUNITY TESTING IN A REVERBERATION CHAMBER
    2000
    Co-Authors: Katsushige Harima, Yukio Yamanaka
    Abstract:

    Testing for immunity against electromagnetic disturbances has become an important aspect of preventing malfunctions in electronic equipment, particularly medical equipment, caused by mobile and other radio transmitters. Radiated immunity tests are generally performed in an anechoic chamber as a standard method [1]. However, reverberation chamber and TEM waveguides, such as a stripline and a TEM-cell, are discussed with IEC and CISPR as an alternative or new testing to conventional measurement, which uses an anechoic chamber [2]-[4]. The reverberation chamber is a Shielded Enclosure equipped with one or more mechanical stirrers [5]-[8]. The stirrers are used to vary the electromagnetic boundary conditions to obtain a statistically uniform field in the chamber. Therefore, the field in a reverberation chamber, in which the direction of polarization changes randomly by the stirrers, is different from that of an anechoic chamber. Determining the number of stirrer positions and measurement locations for a given test volume in a reverberation chamber is important because they affect the uniformity and field calibration of the test volume. We have experimentally evaluated the effect on field uniformity of the number of stirrers, their positions, and the number of locations measured for the case of a reverberation chamber applied to radiated immunity testing.

G. Sindura - One of the best experts on this subject based on the ideXlab platform.

  • Control of electromagnetic waves through electromagnetic shielding
    2011 International Conference on Emerging Trends in Electrical and Computer Technology, 2011
    Co-Authors: G. Sindura, K. Ram Prakash, Peedikakkandy Salil
    Abstract:

    In this paper, propagation of electromagnetic waves around the Shielded Enclosure is analyzed through simulation using MATLAB. Also the importance of electromagnetic shielding and the effect of aperture in Shielded Enclosure are revealed using MATLAB. All electronic equipments emit electromagnetic waves during operation. It can be controlled through electromagnetic shielding. For the equipments to operate well in an electronic environment all equipments are Shielded. Electromagnetic shielding also reduces the hazardous effect to human lives. The most difficult problem in the design of Shielded Enclosure is the presence of apertures. Apertures are included for input/output connection, ventilation, trigger, etc.

  • Modeling and Study of Shielding Effectiveness of Shielded Enclosure and PCB and its Effect due to Loading Effect
    Wireless Communication, 2011
    Co-Authors: G. Sindura, Peedikakkandy Salil, K. Ram Prakash
    Abstract:

    In this paper (i) shielding effectiveness of Shielded Enclosure with single and multiple apertures (ii) Radiation from PCB without shield (iii) Radiation from PCB with shield are analyzed using computational electromagnetic software tool-FEKO. Electromagnetic shielding involves shielding components from electric and magnetic fields and also preventing electronic devices from sending them out. In order to achieve electromagnetic compatibility, mainly with respect to radiated emission and radiated immunity it is required to have a good shielding effectiveness for the equipment Enclosure. Shielding Effectiveness is defined as the ratio of the input field of the unShielded load to that of the Shielded one. The Shielded Enclosure is modelled with both single and multiple apertures. The shielding effectiveness of both Enclosures are found. The PCB is modelled with a ground plane at the bottom and a trace at the top. Then the radiations from PCB are analyzed, before and after the shield. The height of the PCB which is kept inside the Enclosure is varied to find the variations in radiation.