In this contribution we study the propagation constant of interconnects subject to line edge roughness by means of an efficient stochastic framework. By employing the stochastic testing method, we succeed in limiting the number of calls to the full-wave electromagnetic field solver at the core of the system. Additionally, the computationally burdensome solution of the eigenvalue problem is eased by reducing its order through projection on an appropriate basis. The resulting two-step accel-eration leads to an effective approach to assess the effect of line edge roughness on the characteristics of interconnects. The novel framework is applied to a rough rectangular waveguide and a microstrip.

In this contribution, we present a new approach to fully characterize interconnects composed out of arbitrary polygonal cross-sections and containing piecewise homogeneous material parameters. The complex per-unit-of-length inductance and capacitance matrices are obtained through the application of pertinent Dirichlet-to-Neumann operators, which are computed by means of an extended Fokas method, that are integrated in a boundary integral equation approach. As the complete RLGC-data of the structures under study is computed, we are able to assess relevant properties such as signal attenuation and cross-talk while the support for polygonal shapes allows for the inclusion of manufacturing effects such as etching.

A novel technique to accurately characterize interconnects with general, piecewise homogeneous material parameters and arbitrary polygonal cross sections is presented. To compute the per-unit-of-length (p.u.l.) complex inductance and capacitance matrices of the considered structures, we apply a boundary integral equation (BIE) framework, invoking a Dirichlet-to-Neumann (DtN) formalism to recast the problem at hand. The pertinent operators are constructed by means of the numerically fast Fokas method, leveraging fully analytical expressions for the pertinent matrix elements. Numerical examples of various multiconductor transmission lines demonstrate that our proposed scheme is flexible and precise. Since our method is not limited to rectangular cross sections, manufacturing effects such as etching can also be taken into account. Moreover, the examples are not restricted to resistance, inductance, conductance and capacitance (RLGC) data as we also consider signal attenuation, slow-wave factors, and crosstalk.

In state-of-the-art interconnect design, topologies including magnetic materials, such as the so-called superlattice conductors, are rapidly emerging as a novel strategy to handle the challenges associated with the evolution toward higher operating frequencies and integration densities. Consequently, it is imperative that the newly developed full-wave electromagnetic solvers rigorously model these innovative materials and still accurately capture phenomena such as the skin and proximity effect in good conductors. In this article, we propose such a method to rigorously characterize this important class of interconnects with arbitrary, possibly frequency-dependent, material properties, including combined dielectric and magnetic contrast. To that end, a 2-D differential surface admittance (DSA) operator is used, which invokes a single-source equivalence theorem to model both nonmagnetic and magnetic conductors efficiently. This operator is combined with the electric field integral equation (EFIE), yielding a comprehensive formalism to extract the pertinent per-unit-of-length (p.u.l.) resistance and inductance parameters of the modeled structures. The numerical properties of our technique are studied in detail, with particular attention to the influence of magnetic materials. Finally, various relevant application examples are considered to establish its correctness and versatility.

In this contribution, we propose a novel approach to rigorously model interconnect structures with an arbitrary convex polygonal cross-section and general, piecewise homogeneous, material parameters. A full-wave boundary integral equation formulation is combined with a differential surface admittance approach, invoking an extended form of the numerically fast Fokas method to construct the pertinent operator. Several examples validate our method and demonstrate its applicability to per-unit-of-length resistance and inductance characterization.

An electromagnetic interference (EMI) assessment of mmWave interposers becomes increasingly important as the need for heterogeneous systems increases. However, the small size and complexity of these platforms make it more difficult to accurately measure them and, thus, a dedicated set-up to isolate the interposer’s emission is required. In this contribution, we first show experimentally that at mmWave frequencies surface waves originating on the interposer test vehicles may interact with the larger measurement board and severely impact the radiation pattern and maximum electric field strength. Second, a simulation study into the exact origins confirms these surface waves indeed to be at the heart of this issue and calls for appropriate measures in interposer design to prevent any EMI complications when integrating this component in a larger system.

This article presents a novel method to accurately simulate electromagnetic scattering at homogeneous polygonal cylinders with arbitrary material properties. A single source equivalence approach is invoked, allowing to substitute the background medium for the inner material of the scatterer, provided an equivalent surface current density is introduced. We construct the pertinent differential surface admittance operator by means of the Fokas method, establishing a map between the known Dirichlet boundary values and their unknown Neumann counterparts. However, to allow for lossy materials, we extend the Fokas method to complex wavenumbers. The novel formalism, employing pulse-shaped local basis functions, natively supports combined magnetic and dielectric contrast, accurately captures the skin effect, and is conveniently integrated in traditional boundary integral equation formulations. The correctness and versatility of our technique are verified for various examples by means of analytical validation and through comparison with a Poggio-Miller-Chan-Harrington-Wu-Tsai approach, a volume integral equation method and a commercial solver.

In this paper, we present a novel technique to accurately model scattering phenomena at two-dimensional circular and rectangular structures consisting of arbitrary homogeneous materials, including magnetic media in particular. The proposed formalism utilizes a differential surface admittance operator, which invokes a single source equivalence theorem to replace the inside material by its surrounding medium, while introducing an equivalent surface current density. The arbitrary magnetic contrast can be combined with an arbitrary electrical conductivity. As such, the skin effect is rigorously taken into account, making our method ideally suited for broadband modeling of good conductors as well. It is demonstrated that an appropriate choice of the basis functions for the discretized problem is critical to obtain a convergent result when magnetic contrast is introduced. The method is analytically validated for the case of a circular cylinder and additional numerical results illustrate the correctness of the technique for (combinations of) rectangular cylinders, through comparison with a Poggio-Miller-Chan-Harrington-Wu-Tsai approach, a volume integral equation method and a commercial solver.

The aim of this contribution is to study the effect of roughness on the propagation constant in interconnect structures. For this purpose, a stochastic framework is constructed around a full-wave electromagnetic field solver. To reduce the number of repeated calls to the full-wave simulator, two sparse stochastic techniques have been implemented and tested. A balance between calculation time and accuracy is sought for and found, which is demonstrated for a rough rectangular waveguide.

A cost-effective, compact, and high-performance antenna element for beamforming applications in all fifth-generation (5G) New Radio bands in the [24.25–29.5]$ \,$GHz spectrum is proposed in this letter. The novel antenna topology adopts a square patch, an edge-plated air-filled cavity, and an hourglass-shaped aperture-coupled feed to achieve a very high efficiency over a wide frequency band in a compact footprint ($\boldsymbol{{0.48} \lambda _0 \times \text{0.48}\lambda _0}$). Its compliance with standard printed circuit board (PCB) fabrication technology, without complex multilayer PCB stack, ensures low-cost fabrication. The antenna feedplane offers a platform for compact integration of active electronic circuitry. Two different modular 1 $ \boldsymbol{\times }$ 4 antenna arrays were realized to demonstrate its suitability for broadband multiantenna systems. Measurements of the fabricated antenna element and the antenna array prototypes revealed a $-$10 dB impedance bandwidth of 7.15 GHz (26.8%) and 8.2 GHz (30.83%), respectively. The stand-alone antenna features a stable peak gain of 7.4$ \,\pm \,$0.6$ \,$dBi in the [24.25–29.5]$ \,$GHz band and a measured total efficiency of at least 85%. The 1 × 4 array provides a peak gain of 10.1$ \,\pm \,$0.7$ \,$dBi and enables grating-lobe-free beamsteering from ${-}\text{50}^\circ$ to $ \text{50}^\circ$.

A novel substrate-integrated waveguide parasitic compact antenna array without feeding network is proposed for operation in the 24 GHz Industrial, Scientific, and Medical (ISM) band. Inductive windows are exploited to couple adjacent array elements, eliminating the need for a conventional elaborate feeding network, consisting of multiple stages of power dividers. As such, this coupling technique results in an extremely compact design, facilitating integration in close proximity with active devices. Moreover, the insertion loss and the parasitic radiation from the feeding network are significantly reduced, improving the overall energy efficiency. The amplitude distribution is optimized by tuning the amount of coupling between the adjacent array elements, effectively eradicating the side lobes in the radiation pattern’s H-plane and minimizing them in the E-plane. An impedance bandwidth of 315 MHz is obtained, covering the entire 24 GHz ISM band. A 3 dB beamwidth of 43° and 46° in the H-plane and E-plane, respectively, is measured, with a broadside array gain of 10.2 dBi.