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Ludick D.J.,EM Software and Systems S.A. Pty Ltd | Jakobus U.,EM Software and Systems S.A. Pty Ltd | Vogel M.,EM Software and Systems Inc.
8th European Conference on Antennas and Propagation, EuCAP 2014 | Year: 2014

Characteristic mode analysis (CMA) is a useful design tool that enables antenna designers to follow a nonbrute force approach of systematically extracting the radiating properties of a structure. These properties are quantified with CMA in the form of eigenvalues and eigenvectors, i.e., the solutions of a generalised eigenvalue equation that is formulated from the Method-of-Moments (MoM) impedance matrix. One particular challenge to CMA, however, is the manner in which quantities such as eigenvalues are plotted as a function of frequency. At each discrete frequency sample, the eigenvalues are sorted according to modal significance, i.e., based on the efficiency with which they radiate. At higher frequencies, the ordering of modes may differ from that obtained at lower frequencies. To mitigate this problem, we have developed a tracking algorithm to keep the ordering of modes as consistent as possible over frequency. © 2014 European Association on Antennas and Propagation.


Gampala G.,EM Software and Systems Inc. | Reddy C.J.,EM Software and Systems Inc. | Stabler O.,AWE Communications GmbH | Hager T.,AWE Communications GmbH
Microwave Journal | Year: 2012

A compact antenna design that minimizes the space requirements and still achieves low correlation is presented. An electrically small antenna (ESA) that can offer low correlation is used. Also, a self- resonant ESA is designed to match standard transmission lines while still offering good port-to-port isolation. As deterministic ray tracing models can cope best with propagation ray elements is rather small, the same propagation effects, the prediction of the channel capacity is based on a ray tracing wave propagation simulation. The channel capacity is evaluated for LTE systems in urban and indoor environments using different MIMO configurations in the 2.6 GHz frequency band. It is found that the first configuration considers two antenna elements at the base station and one dual port ESA at the mobile handset. The second system uses the same base station equipment, but two dual port ESAs at the lower corners of the handset.


Gampala G.,EM Software and Systems Inc. | Reddy C.J.,EM Software and Systems Inc.
2013 USNC-URSI Radio Science Meeting (Joint with AP-S Symposium), USNC-URSI 2013 - Proceedings | Year: 2013

Long-Term Evolution (LTE) technology implements MIMO for higher data rates that need multiple antennas on the mobile handset (G. Gampala, et al., Microwave Journal, March 2012). At the same time, there is also an increased pressure on the design engineers to come up with attractive thinner and slimmer phones, leaving very little space for the antenna engineers. © 2013 IEEE.


Jiang R.,China Telecom | Wang C.,EM Software and Systems Inc.
Proceedings of 3rd Asia-Pacific Conference on Antennas and Propagation, APCAP 2014 | Year: 2014

This paper presents a procedure of designing an offset Gregorian dual-reflector antenna with a non-circular aperture of the main reflector using FEKO. A 1.2m Ku band offset dual-reflector antenna is set as an example to compare the results from two solvers in FEKO with the measurement data. There are good agreements on the radiation patterns simulated in FEKO with those by measurement. © 2014 IEEE.


Reddy C.J.,EM Software and Systems Inc. | Peterson A.,Georgia Institute of Technology
IEEE Antennas and Propagation Magazine | Year: 2011

The Applied Computational Electromagnetics Society (ACES) provides a forum for issues relevant to numerical modeling in applied electromagnetics. The primary focus of ACES is on computational techniques, electromagnetics modeling software, and applications. The Applied Computational Electromagnetics Society offers the ACES annual symposium, publications, code user groups, benchmark-problem solution workshops, short courses, software demonstrations, and other activities. © 2011 IEEE.


Campbell D.,EM Software and Systems Inc. | Gampala G.,EM Software and Systems Inc. | Reddy C.J.,EM Software and Systems Inc. | Winebrand M.,ORBIT FR Inc. | Aubin J.,ORBIT FR Inc.
Applied Computational Electromagnetics Society Journal | Year: 2013

Advances in computational resources facilitate anechoic chamber modeling and analysis at VHF/UHF frequencies using full-wave solvers available in commercial software such as FEKO. The measurement community has a substantial and increasing interest in utilizing computational electromagnetic (CEM) tools to minimize the financial and real estate resources required to design and construct a custom anechoic chamber without sacrificing performance. A full-wave simulation analysis such as the finite element method (FEM) provides a more accurate solution than the approximations inherent to asymptotic ray-tracing techniques such as physical optics (PO), which have traditionally been exploited to overcome computational resource limitations. An anechoic chamber is simulated with a rectangular down-range cross-section (in contrast with the traditional square cross-section) to utilize the software's capability to assess polarization performance. The absorber layout within the anechoic chamber can be optimized using FEKO for minimal reflections and an acceptable axial ratio in the quiet zone. Numerical results of quiet zone disturbances and axial ratios are included for both low- and medium-gain source antennas over a broad frequency range. © 2013 ACES.


Gampala G.,EM Software and Systems Inc. | Sammeta R.,EM Software and Systems Inc. | Reddy C.J.,EM Software and Systems Inc.
Microwave Journal | Year: 2010

A demand for low-profile antenna designs is met by the use of high impedance surfaces (HIS), which can essentially be considered as artificial magnetic conductors. The HIS is realized by printing the periodic array of frequency selective surfaces (FSS) over a metal-backed dielectric substrate. The initial design of the FSS structure with broadband characteristics is optimized for sharp narrow band characteristics. The reflectivity characteristics of the HIS ground planes is realized using the un-optimized and the optimized FSS structures, revealing the correlation between the FSS and the HIS. The effect of the substrate length and width on the impedance characteristics of the antenna is studied as the overall size of the antenna, including the HIS ground plane, is important for use in compact mobile devices.


Gampala G.,EM Software and Systems Inc. | Reddy C.J.,EM Software and Systems Inc. | Ludick D.,EM Software and Systems S.A. Pty Ltd. | Futter P.,EM Software and Systems S.A. Pty Ltd.
IEEE Antennas and Propagation Society, AP-S International Symposium (Digest) | Year: 2014

Mobile communications technology is constantly changing with the increasing demands of the consumers and Long Term Evolution (LTE) is widely accepted as the technology that can meet these requirements. This paper presents an electrically small antenna designed for European LTE frequency band of 1800MHz. A systematic design procedure is developed using characteristic mode analysis (CMA). The CMA design procedure provides needed insights for the antenna designers to quickly come up with an antenna design using an arbitrarily shared structure. © 2014 IEEE.

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