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The straight forward scaling of the planar ultra-wideband modular antenna (PUMA) array to UHF or lower frequencies poses significant manufacturing challenges. A new PUMA unit cell was conceived which allows up to 6:1 bandwidth and 45° scanning to be realized in the UHF band. The unit cell contains a printed dipole layer that is fed through vertical stripline cards. A standard, off-the-shelf bolt is...
A memory-efficient exact arithmetic direct solution method for sparse linear systems arising from the Finite Element Method (FEM) is outlined. The proposed method is based on a novel symmetric domain decomposition method (DDM) with one set of Lagrange multipliers that is applicable to a large class of methods arising from the Galerkin partial differential equations (PDEs). Comparisons with state-of-the-art...
This work presents the development of a low cross-polarization ultra-wideband end-fire notch array element, termed the Sliced Notch Antenna (SNA). The proposed element topology solves the long-standing problem of polarization purity degradation in typical end-fire notch arrays (Vivaldi arrays) when scanned in the non-principal planes by re-configuring the high-profile continuous metal Vivaldi fin...
A parallel computational framework of finite element domain decomposition method (FE-DDM) is presented. Specifically, the randomized computation of domain Dirichlet-to-Neumann (DtN) operators and a robust randomized-based W-FETI preconditioning technique are integrated in a parallel implementation. Numerical examples are given to show the parallel scalability, accuracy and efficiency of the presented...
An exact arithmetic, memory efficient direct solution method for finite element method (FEM) computations is outlined. Unlike conventional black-box or low-rank direct solvers that are opaque to the underlying physical problem, the proposed method leverages physical insights at every stage of the development through a new symmetric domain decomposition method (DDM) with one set of Lagrange multipliers...
The wavelength-scaled array architecture reduces element count and associated T/R module costs by replacing a portion of a periodic array by fewer, but scaled up elements that are excited only at lower frequency bands. We propose the implementation of the wavelength-scaled array using low-cost Planar Ultrawideband Modular Antenna (PUMA) radiators to further reduce cost, profile and improve polarization...
This paper discusses bandwidth and polarization challenges in modern dual-polarized ultra-wideband (UWB) electronically scanned array (ESA) aperture design and two recent solution advances aiming to remedy such issues: a 6:1 Planar Ultrawideband Modular Antenna (PUMA) array and a 10:1 Sliced Notch Antenna (SNA) array. The proposed arrays enable wide bandwidth, low cross-polarization, and high efficiency...
The proposed Sliced Notch Antenna (SNA) array fixes the longstanding problem of high cross-polarization radiation in Vivaldi arrays while maintaining their excellent wideband wide-scan impedance performance with a simple reconfiguration of the Vivaldi fins. The enabling technical innovation is the introduction of discontinuities at the upper region of the flared fins that control the ratio of vertical-to-horizontal...
Advances in Planar Ultra-wideband Modular Antenna (PUMA) array architecture which have culminated into a 6∶1 bandwidth design without the use of an external backplane matching network are presented. This paper will examine the additional bandwidth-enhancing operational principles of the proposed dual-polarized 6∶1 PUMA array. A design and its respective full-wave simulations will then be presented,...
An important system design specification for electronically scanned arrays (ESAs) is the polarization purity for certain scan volume. Methods for determining the polarization levels of an array will be discussed and used to quantify finite array truncation effects on polarization purity of ultra-wideband (UWB) arrays. Simulated finite array results are used to examine the polarization properties of...
An efficient and robust FETI-2λ domain decomposition method (DDM) framework for electromagnetic (EM) modeling is outlined. The proposed framework uses randomized algorithms to approximate the low-rank discrete Dirichlet-to-Neumann (DtN) map interations that arise in FETI-2λ. The resulting approach is also combined with effective and robust local and global DDM preconditioners. A realistic numerical...
A single-polarized, decade-bandwidth Vivaldi array with low cross-polarization is proposed. The array, termed the Sliced Notch Antenna (SNA) Array, exhibits the wideband impedance performance of Vivaldi arrays, yet it readily over-comes polarization purity degradation while scanned in the non-principal planes. The critical enabling technical innovation is the control of vertical surface current radiation...
An effective, efficient and robust algebraic global preconditioner for the FETI-2λ Domain Decomposition Method (DDM) is proposed. The new preconditioner is based on the Woodbury matrix identity, termed as W-FETI, and is inspired by the observation that under certain circumstances the discrete Diritch-to-Newmann (DtN) operators of the domains are rank deficient. Numerical examples showcase the excellent...
Often the end product of an electromagnetic simulation is a far-field quantity such as antenna gain, radiated power or radar cross section (RCS). When the underlying CEM solver is a frequency domain domain decomposition finite element method (DD-FEM) which solves for the near-field electric fields, an extra near-to-far-field transformation step must be invoked for each frequency and excitation. Traditionally...
An important consideration when establishing the radiation characteristics of phased arrays is the polarization purity for scan situations, defined as the ratio between the co-/cx-polarization levels at the particular scan. Two accepted methods for determining the polarization levels of an array will be used to quantify finite array truncation effects on polarization purity of ultra-wideband arrays...
Phased array characterization, and electromagnetic (EM) and circuit (CKT) co-simulation of packaging, components and PCBs both involve large number of ports. As such, obtaining their transfer (system) function matrix requires multiple simulations, each with a different port excitation. Even fast methodologies such as the model order reduction (MOR) and other fast CEM methods, experience severe slow-down...
A new class of Planar Ultrawideband Modular Antenna (PUMA) arrays, the PUMAv3, is introduced. PUMAv3 is scalable to mm-wave frequencies (≈50 GHz) and improves bandwidth by 50% without the use of a matching network or external baluns. The enabling technical innovations include a new feeding mechanism that relies on capacitively loaded shorting vias and an alteration on the superstrate loading scheme...
We outline a scalable and robust finite element Domain Decomposition Method (DDM) in Computational Electromagnetics (CEM). The methodology is based on the effective and efficient preconditioning of the Finite Element Tearing and Interconnecting (FETI) matrix via a fully algebraic, local preconditioner called the Locally Exact Algebraic Preconditioner (LEAP), combined with a global macro-basis multi-grid...
Often the end product of an electromagnetic simulation is a far-field quantity such as antenna gain, radiated power or radar cross section (RCS). When the underlying CEM solver is a frequency domain finite element method which solves for the near-field electric fields, an extra near-to-far-field transformation step must be invoked for each frequency and excitation. Traditionally this step involves...
A matching network is integrated into the latest version of the PUMA array (presented in a fellow paper [1]) to increase the bandwidth. The PUMAv3.2 is scalable to mm-wave frequencies (≈45 GHz) and increases bandwidth from 4.5∶1 to 6∶1. We investigate the difficulties and possible solutions associated with integrated matching network PUMA designs. Part of the enabling technical aspects is a capacitively...
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