C. J. Reddy

Characteristic Mode Analysis: Putting Physics back into Simulation

Characteristic-mode analysis (CMA) enables a systematic approach to antenna design and antenna placement. The approach is based on insight in the fundamental resonance characteristics of antenna geometries and of the structures on which they are mounted. This insight aids in choosing the locations of excitations on an antenna and of the antennas on a platform. Furthermore, knowledge of the coupling between excitations and modes enables a design engineer to synthesize the desired antenna pattern by exciting a linear combination of modal patterns. This is a deterministic approach, which is based on insight in physics. It contrasts with an approach in which an optimization routine is used to explore a large many-dimensional design space with few constraints. This paper offers a refresher on the theory of characteristic modes and presents practical examples that all use CMA in the design process and in the interpretation of results.

Design of millimeter wave antenna arrays for 5G cellular applications using FEKO

The technologies under development in the world of mobile broadband networks specifically focusing on the next generation of standards, namely 5G, are targeting the millimeter wave spectrum of 28 GHz and beyond. This paper discusses some of these futuristic technologies that are laying the foundation for the 5G standards, highlighting the concept of massive MIMO that employs antenna arrays and beamforming techniques to address the high data rate demands.

Compact LTE antenna design using the theory of characteristic modes for smart phone applications

Summary form only given. 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. This paper presents a novel electrically small antenna designed for the European LTE frequency band of 1800 MHz. The theory of characteristic modes (D. J Ludick, et al., ICEAA.2012, 208-211) used to come up with the presented design within the given limited space. Characteristic modes are real current modes that depend only on the shape and size of the geometry. Given the shape and size of the mobile handset, and the available space for the antenna, characteristic modes are computed for the geometry using commercial EM simulation tool, FEKO (www.feko.info). The antenna design is optimized by cutting out slots in the geometry with zero modal currents. Two antennas, orthogonally oriented to each other to provide the space and polarization diversity, are integrated into the mobile handset with the PCB acting as the ground plane, as shown in Fig.1. More results with the detailed process of the antenna design will be presented at the conference.

Systematic design of antennas using the theory of characteristic modes for mobile phone applications

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 1800 MHz. 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.

Advanced computational tools for phased array antenna applications

This paper investigates the applicability of various Computational Electromagnetic (CEM) Methods for the design and analysis of phased array antennas. The full-wave methods like the Method of Moments (MoM), Finite Element Method (FEM), Finite-Difference Time-Domain (FDTD) and Multi-level Fast Multipole Method (MLFMM) are discussed in detail starting with simple arrays like a planar strip dipole to more complex Vivaldi antenna arrays. The usefulness of special features like the Periodic Boundary Conditions (PBCs) and the Domain Greens Function Method (DGFM) is also investigated.

Aces Corner [ACES Corner]

Reports on the activities and awards presented at the 2015 Applied Computational Electromagnetics Society (ACES) Conference.

Fast Prototyping of Near-Field Antennas for Magnetic Resonance Imaging by Using MoM Simulations and 3D Printing Technology

Near-field antennas are critical to the performance of magnetic resonance imaging (MRI). Unlike conventional antennas designed for far-field radiation, there are rather strict geometric requirements, such as conformity and symmetry. We present a fast-prototyping approach that combines accurate electromagnetic simulation and 3-D printing technology, in order to meet the design requirements. A unique feature of this approach is the precise translation of coil model in electromagnetic simulations to mechanical design that can be manufactured directly by 3-D printing. Two examples are given to demonstrate the validity and effectiveness of this approach.

The 2015 Student Paper Competition [ACES Corner]

A student paper competition is held during every Applied Computational Electromagnetics Society (ACES) conference to provide an opportunity for students to present their research in applied computational electromagnetics in a special student paper competition session and to compete for cash prizes. ACES requires that the competitions participants be student authors of the papers. As it is the tradition at all ACES conferences, a student paper competition was held at ACES 2015. The winners of the competition were mentioned in the June 2015 issue of IEEE Antennas and Propagation Magazine. In this issues column, the abstracts of the five winning papers are given.