Substrate Integrated Waveguide Circuits Research Articles

Detection of the Defective Vias in SIW Circuits From Single/Array Probe(s) Data Using Source Reconstruction Method and Machine Learning

In this article, a new approach to detect the defective vias in substrate-integrated waveguide (SIW) structures is proposed. First, very near-field radiations of SIW structures are measured using either a single magnetic field probe or a fast electronically switched probe array. A source reconstruction method is utilized to calculate the equivalent electric and magnetic currents on the surface of the SIW structure under investigation. Thereafter, these equivalent sources are used to obtain the magnetic fields very close to the sample boards. A machine learning algorithm is used to distinguish the radiations that are due to the defective vias from those because of radiating parts of the circuit such as feed lines. The simulation and measurement results confirm the validity and accuracy of this high-resolution method.

A Wideband Correlation and Detection Module Based on Substrate-Integrated Waveguide Technology for Radio Astronomy Applications

A wideband (30% relative bandwidth) correlation and detection module based on substrate-integrated waveguide (SIW) technology intended for a radio astronomy polarimeter is presented. The SIW circuit is a six-port network with two input ports that are correlated in two hybrid couplers and their corresponding output signals are routed to Schottky diode detectors, which are designed using microstrip technology and assembled within the same system. The designed SIW structure includes hybrid couplers, power dividers, a 90° phase shifter, and 90° bends, providing a real implementation of a functional system with improved bandwidth performance from 35 to 47 GHz. Experimental results are in concordance with simulations, and they validate the module operation for the proposed application.

Overall Formulation for Multilayer SIW Circuits Based on Addition Theorems and the Generalized Scattering Matrix

This letter presents a multilayer formulation for substrate integrated waveguide circuits, based on the analytical connection of cylindrical modes of sections described by their generalized scattering matrix (GSM). Sections containing arbitrary elements, defined by feeding and cylindrical ports, are analyzed using the finite element method with fast frequency sweep to obtain their GSM.

Efficient Modeling and Analysis of the Multiple Air Hole Effect in Substrate-Integrated Waveguide

A wide spectrum of potential applications using substrate-integrated waveguide (SIW) technologies in conjunction with air hole regions is introduced, and an efficient analysis method to cope with the multiple air hole effect in the SIW is proposed where we present the generalized wave equation satisfying the boundary and phase matching conditions to solve the multiple air interface problem, which provides highly accurate dispersion characteristics over the whole frequency band. The proposed approach is compared with a commercial software and verified by measurement results from the fabricated samples using Taconic/RF30-7H substrate, and is confirmed to give excellent agreement. Hence, the proposed method is effective for optimum design of SIW circuits for the purpose of low-loss and broadband applications.

Special Issue on Substrate integrated Waveguide Circuits and Systems for MHz-Through-THz Wireless and Photonics Applications

Special Issue on Substrate integrated Waveguide Circuits and Systems for MHz-Through-THz Wireless and Photonics Applications

Substrate-Integrated-Waveguide E-Plane 3-dB Power-Divider/Combiner Based on Resistive Layers

Several different microwave circuits, including beamforming networks and balanced amplifiers, make use of 3-dB power dividers and combiners. A well-known architecture able to work over large bandwidths, a critical request for many applications, is based on E-plane three-port waveguide structures, where a lossy element is added to overcome the inherently poor isolation given by lossless three-port junctions. While a standard implementation based on normal rectangular waveguides often results in large and heavy structures, an implementation based on substrate-integrated-waveguide (SIW) technology offers advantages in terms of compactness, weight reduction, cost minimization, and integration possibilities with active stages. This paper presents the design, fabrication, and characterization of two SIW E-plane 3-dB power divider/combiners where the lossy element is realized using a resistive layer. The prototypes cover the entire X-band from 8 to 12 GHz, and the resistive layers are realized according to two different manufacturing techniques to investigate the potentials of both approaches. The optimization of the resistive layer geometry and resistivity, a critical aspect for low-profile SIW circuits, is discussed in detail. In particular, an analytical formula is derived, which allows to determine the optimum values for the resistive layers' principal parameters, namely the length and resistivity, without the use of full-wave numerical solvers.

Ka‐band compact and high‐performance bandpass filter based on multilayer air‐filled SIW

A substantial reduction of Substrate Integrated Waveguide (SIW) insertion loss can be achieved through the use of air as dielectric instead of usual dielectric material. However, Air-Filled SIW (AFSIW) circuits exhibit larger footprint compared to their dielectric-filled counterparts. In this letter, a compact multilayer AFSIW bandpass filter is proposed to realize both high performance and small footprint. For demonstration purpose, a Ka-band multilayer 4th order AFSIW bandpass filter has been designed and fabricated. Measured and simulated results are in good agreement. Retro-simulations, taking into account fabrication tolerances, are also presented. Finally, a performance comparison with other multilayer technologies is presented.

Revisiting and improvement of thru‐reflect‐line calibration for accurate measurement of substrate integrated waveguide components

Thru-reflect-line (TRL) calibration method were reviewed and the related kits based on substrate integrated waveguide (SIW) were re-examined, designed, and compared for measurements of SIW circuits. Different types of calibration kits were discussed and the design guidelines were provided. Filters working at 5 and 10 GHz were designed for the verification purpose of these calibration kits. Meanwhile, the TRL calibration method based on uniform SIW-coaxial transitions was proposed, which shows improved measurement accuracy.

Accurate and efficient study of substrate-integrated waveguide devices using iterative wave method

This paper proposes an efficient and fast analysis of substrate integrated waveguide (SIW) components using a new approach of the iterative method called WCIP, i.e. “Wave Concept Iterative Process”. This method is based on the iterative resolution of waves between two domains. The first is the spectral domain. We use the Floquet–Bloch decomposition to describe all modes in the spectral domain. The second describes the configuration of the circuit in the spatial domain. It allows taking the exact structure according to the appropriate boundary conditions. This method permits to reduce numerical complexity. The convergence of this approach is always guaranteed. The theoretical suggested study is validated by the simulation of two different examples of SIW circuits. The obtained results are in good agreement with those of measurement and with software HFSS simulations, which prove the advantage of this method.

Substrate‐integrated waveguide matching terminations with microwave absorbing material

Substrate integrated waveguide (SIW) matching terminations or loads are proposed for low-cost integration in SIW circuits and systems. The principles of narrowband and broadband SIW terminations are demonstrated and discussed. Both narrowband and broadband terminations are optimised, fabricated and measured over the frequency range of 6–15 GHz. Relative frequency bandwidths (|S11| < 20 dB) of the narrowband and broadband terminations are 7.6 and 42.6%, respectively. Good agreement between the measured and simulated results validates the feasibility of the proposed design strategies of SIW terminations.

An X‐band substrate integrated waveguide attenuator

ABSTRACTAn X‐band substrate integrated waveguide (SIW) attenuator is presented for the first time. To gain the desired attenuation level, a resistive π‐network was structured using standard surface‐mount device resistors while retaining a predefined mode transition and impedance matching condition. The attenuator prototype features the measure of attenuation level (−1, −3, and −5dB) across 8.04–11.12 GHz frequency range. The attenuator may contribute to design of a genuine SIW circuit. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:2446–2449, 2014

대 면적 기판 집적 PDN의 위상차 문제를 제거하기 위한 유전체 나사를 이용한 가변 기판 집적 도파관

본 논문에서는 대 면적 기판 집적 도파관 전력 분배 네트워크(Substrate Integrated Waveguide Power Distribution Network: SIW PDN)의 출력 단자 간 위상차를 제거하기 위해 유전체 나사를 적용한 가변 기판 집적 도파관(SIW: Substrate Integrated Waveguide)을 제안한다. 본 제안 구조는 가변 기판 집적 도파관에 비 도금된 비아 홀에 부분적으로 유전체 나사를 삽입하여 S-parameter의 크기에 거의 영향을 주지 않고 위상 천이를 이룬다. 이로써, 유전체 나사가 삽입되지 않은 가변 기판 집적 도파관이 적용된 대 면적 SIW PDN(<TEX>$370\;mm{\times}195\;mm$</TEX>)의 측정된 <TEX>${\pm}33.9^{\circ}$</TEX>의 위상 차이가 본 제안 구조를 통하여 <TEX>${\pm}4.65^{\circ}$</TEX>까지 크게 감소되었다. 본 논문에서 제안된 유전체 나사를 이용한 가변 SIW는 향후 초경량, 고성능 기판 집적 위상 배열 시스템 및 대 면적 SIW 회로 응용에 중요한 역할을 할 것으로 기대된다. In this paper, we propose a tunable SIW(Substrate Integrated Waveguide) using dielectric screws for eliminating the phase imbalance of large size power distribution networks(PDN). Alumina screws partially inserted into several through holes of the tunable SIW section effectively change the phase shift without S-parameter degradation. <TEX>${\pm}33.9^{\circ}$</TEX> measured phase imbalance of a large conventional 9 GHz SIW-PDN of <TEX>$370\;mm{\times}195\;mm$</TEX> size has been greatly reduced to <TEX>${\pm}4.65^{\circ}$</TEX>. We expect that the proposed tunable SIW plays an important role for a light-weight, high performance substrate integrated phased array system(Si-PAS) and large size SIW circuit applications.

Analysis and Design of Substrate Integrated Waveguide Using Efficient 2D Hybrid Method

Substrate integrated waveguide (SIW) is a new type of transmission line. It implements a waveguide on a piece of printed circuit board by emulating the side walls of the waveguide using two rows of metal posts. It inherits the merits both from the microstrip for compact size and easy integration, and from the waveguide for low radiation loss, and thus opens another door to design efficient microwave circuits and antennas at a low cost. This book presents a two-dimensional fullwave analysis method to investigate an SIW circuit composed of metal and dielectric posts. It combines the cylindrical eigenfunction expansion and the method of moments to avoid geometrical descritization of the posts. The method is presented step-by-step, with all the necessary formulations provided for a practitioner who wants to implement this method by himself. This book covers the SIW circuit printed on either homogeneous or inhomogeneous substrate, the microstrip-to-SIW transition and the speed-up technique for the simulation of symmetrical SIW circuits. Different types of SIW circuits are shown and simulated using the proposed method. In addition, several slot antennas and horn antennas fabricated using the SIW technology are also given. Table of Contents: Introduction / SIW Circuits Composed of Metallic Posts / SIW Circuits with Dielectric Posts / Even-Odd Mode Analysis of a Symmetrical Circuit / Microstrip to SIW Transition and Half Mode SIW / SIW Antennas

Substrate-integrated waveguide circuit analysis and optimisation

This work proposes a technique for the analysis of electrically large substrate-integrated waveguide (SIW) circuits. For this purpose, the circuit is first decomposed into a number of two or multi-port sub-circuits. A commercial full-wave solver is then used to determine the scattering parameters of these sub-circuits with respect to their reference planes, which are also chosen on their connecting SIWs. Using this type of waveguide as the reference waveguide of the sub-circuits enables us to analyse a large variety of SIW circuits. A library of scattering parameters of mostly utilised sub-circuits or components, such as Y-junctions, bends etc., is generated. The overall scattering parameters of the circuit are then evaluated using a proper connection of the scattering parameters of the SIW sub-circuits. The paper also discusses the conditions under which the proposed analysis provides the desired accuracy. With the help of this method, we have analysed and optimised electrically large SIW circuits, such as a four-way power splitter.

SUBSTRATE INTEGRAGED WAVEGUIDE WILKINSON POWER DIVIDER WITH IMPROVED ISOLATION PERFORMANCE

This work proposes a substrate integrated waveguide (SIW) power divider employing the Wilkinson conflguration for improving the isolation performance of conventional T-junction SIW power dividers. Measurement results at 15GHz show that the isolation (S23, S32) between output ports is about 17dB and the output return losses (S22, S33) are about 14.5dB, respectively. The Wilkinson-type performance has been greatly improved from those (7:0dB » 8:0dB) of conventional T-junction SIW power dividers. The measured input return loss (23dB) and average insertion loss (3.9dB) are also improved from those of conventional ones. The proposed Wilkinson SIW divider will play an important role in high performance SIW circuits involving power divisions.

Multilayer Substrate Integrated Waveguide Four-Way Out-of-Phase Power Divider

In this paper, a multilayer substrate integrated waveguide (SIW) four-way out-of-phase power divider is investigated. In a previous research (Eom , 2009), the four-way power division was studied by a 3-D mode coupling method, which was achieved by a vertical Y-junction as well as a lateral Y-junction of half mode substrate integrated waveguides (HMSIW) using a multilayer substrate. In this research, resistive coupling slots, for obtaining good isolation between four output ports and impedance matching at all the ports, are realized on the lateral HMSIW Y-junctions and the vertical HMSIW Y-junctions using isolation resistors. From the measurement results, excellent performances of insertion loss, isolation, impedance matching, and amplitude balancing were simultaneously achieved for the X-band range. It is expected that the proposed design of a multilayer substrate integrated waveguide (ML-SIW) power divider will play an important role in the future integration of compact multiway SIW circuits and systems.

Ku‐band substrate integrated waveguide transitions between layers

AbstractTwo types of the substrate integrated waveguide (SIW) transitions between layers are presented in this letter. The SIW circuits have been used to achieve the transition from one layer to other layer. These two types of SIW transitions between layers operating in Ku‐band have been designed and fabricated. The measured 10‐dB return loss bandwidth of the transition between adjacent layers is about 7 GHz, and the measured 1‐dB insertion loss bandwidth is about 5 GHz; the measured 13‐dB return loss bandwidth of the unadjacent‐layers transition is demonstrated to be about 3.7 GHz, and the measured insertion losses are less than 2 dB from 11.2 GHz to 15 GHz. The simulated and measured results indicate that these two SIW transitions take the advantages of broadband, low insertion loss, and low profile. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 2585–2588, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24685

Hybrid of Method of Moments and Cylindrical Eigenfunction Expansion to Study Substrate Integrated Waveguide Circuits

A hybrid method that combines method of moments (MOM) and cylindrical eigenfunction expansion is presented to study a substrate integrated waveguide circuit that consists of metallic and dielectric circular cylinders. The problem is considered as a 2-D electromagnetic problem assuming no field variation normal to the dielectric substrate. The scattered field from each circular cylinder is expanded by cylindrical eigenfunctions, and the equivalent current densities at a waveguide port are expanded using the MOM. After enforcing boundary conditions and applying the additional theorem of Bessel and Hankel functions, a set of linear equations are constructed using the orthogonality of the exponential function. With matrix manipulation and sub-ports combination, the <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">S</i> matrix can then be obtained. Four examples are analyzed by using the hybrid method and verified by using Ansoft Corporation's commercial High Frequency Structure Simulator (HFSS) software package. It is shown that the hybrid method runs faster than HFSS and requires less memory. It is also pointed out that the method can be used to study a circuit with noncircular cylinders.

Efficient and accurate design of substrate-integrated waveguide circuits synthesised with metallic via-slot arrays

A new class of substrate-integrated waveguides (SIWs) is proposed, which highlights a novel synthesis of waveguide circuits using metallic via-slot arrays instead of via-hole arrays. When the gaps between the slots are small enough, the broadside dimension of equivalent rectangular waveguide is approximately equal to the spacing between the inner walls of slots. Therefore the size of the SIW can directly be used to calculate propagation constants almost without phase bias. This new design is of critical importance in the design of substrate-integrated circuits (SICs) with fine and sensitive geometrical details with respect to circuit response such as filters and resonators. In this way, the design of SICs based on the new SIW structures can greatly be simplified. A finite difference frequency-domain method accelerated by an implicitly restarted Arnoldi method is developed to model the substrate-integrated resonant cavities with leakage. Simulated and measured results have confirmed the fact that conventional waveguide components are very similar to the SIW counterparts of the same structure.

W-band multiport substrate-integrated waveguide circuits

Millimeter-wave passive circuits that are designed and fabricated in the form of substrate-integrated waveguide (SIW) are presented in this paper. A W-band SIW 90/spl deg/ hybrid coupler and multiport SIW circuit are made and synthesized on alumina substrate using metallized slot arrays. In order to connect the SIW circuits with WR-10 standard rectangular waveguides for measurement purposes, a new transition is also proposed and developed. Such millimeter-wave integrated passive circuits are developed for applications in radar sensors operating at 94 GHz. Performances of these circuits are evaluated and discussed on the basis of a series of S-parameter simulations and measurements. Excellent agreement between simulated and measured results is observed.