Substrate Integrated Waveguide Components Research Articles

Coplanar Meta-Surface-Based Substrate-Integrated Waveguide Antennas with Broadband and Low Reflections for K-Band Beam Scanning.

Four novel substrate-integrated waveguide (SIW) antennas are proposed, in order to obtain K-band beam scanning through the coplanar meta-surfaces of properly devised complementary split-ring resonators. More specifically, coplanar rhombus- and hexagon-shaped meta-surfaces replace the metallized via holes in the traditional SIW structure, achieving low reflection and wide bandwidth, respectively. Another trapezoid-shaped meta-surface is introduced, in order to realize good leaky-wave radiation performance with high-gain beam scanning in both rhombus- and hexagon-shaped SIW components. These designs are further extended to two different mixed types of two-row meta-surfaces, with the rhombus and hexagon structures combined in different orders to enhance the complex SIW transmission lines and antennas, which can simultaneously obtain good reflection and bandwidth with different priority, depending on the arrangement. We explain the performance differences with rhombus and hexagon meta-surfaces through the analysis of relevant equivalent circuit models and extracting the effective medium parameters, and we verify the bandwidths and radiations of four SIW antennas both numerically and experimentally. The maximum gains of the four antennas are 18.1 dBi, 17.0 dBi, 18.8 dBi and 17.1 dBi, where the corresponding relative bandwidths are 10.74%, 19.42%, 14.13% and 18.38%. The maximum simulated radiation efficiency and aperture efficiency of the proposed antennas are 91.20% and 61.12%, respectively. Our approach for generating flexible and selectable tuned electromagnetic fields from SIWs is applicable for the development of mm-Wave antennas or sensors on PCB-integrated platforms for highly directive scanning radiation.

Fully planar slow‐wave substrate integrated waveguide based on broadside‐coupled complementary split ring resonators for mmWave and 5G components

The authors propose a new metamaterial-inspired substrate integrated waveguide (SIW) that utilises broadside-coupled complementary split ring resonators (BC-CSRRs) instead of metalised via holes, to confine propagation within the guiding channel. Due to the resonant behaviour of the BC-CSRRs, blocking of in-plane propagation is achieved in a straightforward and efficient manner. The final waveguide is synthesised by employing two rows of CSRRs instead of each via row, resulting in a fully-planar, easy to fabricate, cost-effective solution. This new waveguide exhibits outstanding propagation characteristics, with losses close to those of the conventional SIW, providing a highly promising platform to implement low-cost planar components for millimetre-wave applications. To further confirm the potential of implementing CSRR-based SIW components, they provide designs of leaky-wave antennas in the X- and Ka-band, utilising this new concept.

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.

Innovative manufacturing approach for paper‐based substrate integrated waveguide components and antennas

This study presents a novel low-cost manufacturing technique for paper-based microwave components. In particular, this work is focused on the implementation of substrate integrated waveguide (SIW) passive circuits and antennas. The proposed manufacturing technique requires the preliminary preparation of the metallised paper substrate, obtained by stacking different layers of paper, and eventually gluing two aluminium foils on both faces of the paper substrate. Subsequently, the circuit pattern is obtained by milling machining. Finally, as the SIW structures require metal vias, cylindrical holes are obtained by drilling and then metallised by conductive paste, by adopting a particular technique. The different steps are detailed in this study, and the basic features of the proposed technique are compared with the traditional ink-jet-printing technology typically used for paper-based microwave circuits. Moreover, the fabrication and testing of several SIW components and antennas are presented in a comprehensive way, to demonstrate the potential of the proposed manufacturing technique and its applicability to the development of the next generation of eco-friendly wireless systems.

Cost-effective and Green Manufacturing Substrate Integrated Waveguide (SIW) BPF for Wireless Sensor Network Applications

This paper presents a comparison between innovative technique for implementation of substrate integrated waveguide band pass filter centered at 4 GHz and conventional PCB results . Two poles filter is designed, simulated and fabricated. The novel fabrication process technique is based on green manufacturing where physical etching of metal layer of aluminum is glued on paper substrate. The pass band filter is composed of two resonant adjacent and symmetric cavities separated by a coupling iris. The same topology is adopted with conventional substrate and PCB technology to validate the new technique results. The bandwidth achieved is almost four times wider than found with PCB technology developed for UWB applications. The proposed technique keeps the advantages of conventional SIW technology including low profile, compact size, complete shielding, easy fabrication, low cost for mass production as well as convenient integration with planar waveguide components including transitions. Moreover, the flexible quality of paper offer the possibility to fabricate conformal shapes of SIW components which is not possible with conventional rigid substrates made with PCB technology . In addition to the advantages of eco friendly, renewable, light weight , and ultra low cost materials

Additive manufacturing of 3D substrate integrated waveguide components

The implementation of fully three-dimensional (3D) substrate integrated waveguide (SIW) components by using an additive manufacturing technique is demonstrated for the first time. In particular, a 3D printing process based on the t-glase filament has been adopted. 3D printing allows for the manufacturing of very complex shapes in a few hours, thus leading to a one-day prototyping time for microwave components. To characterise the electromagnetic properties of the 3D printed material, a microstrip lines technique has been adopted. To fully demonstrate the potential of the proposed fabrication process, a SIW cavity resonator and a 3D SIW interconnect with four E-plane bends have been fabricated and tested.

Textile Microwave Components in Substrate Integrated Waveguide Technology

Although substrate integrated waveguide (SIW) technology is well established for the fabrication of microwave circuits on rigid printed circuit boards, and the first implementations of textile SIW antennas have recently appeared in literature, up to now, no complete set of SIW microwave components has been presented. Therefore, this paper describes the design, manufacturing, and testing of a new class of textile microwave components for wearable applications, implemented in SIW technology. After characterizing the adopted textile fabrics material in terms of electrical properties, it is shown that folded textile SIW components, such as interconnections, filters, and antennas form excellent building blocks for wearable microwave circuits, given their low profile, flexibility, and stable characteristics under bending and in proximity of the human body. Hence, they allow the full exploitation of the large area garments offered for the deployment of wearable electronics. Besides SIW interconnections, a folded textile SIW filter operating at 2.45 GHz is designed and tested. The filter combines excellent performance in the band of interest with good out-of-band rejection, even when accounting for the tolerances in the fabrication process. Finally, a folded SIW cavity-backed patch antenna is fabricated and experimentally verified in realistic operating conditions.

SUBSTRATE INTEGRATED WAVEGUIDE DESIGN USING THE TWO DIMENTIONNAL FINITE ELEMENT METHOD

In this paper, a rigorous and accurate numerical two-dimensional modeling flnite element method 2D-FEM is applied to the analysis and design of substrate integrated waveguide components. The flnite element method represents an excellent tool for the analysis and design since it easily allows taking into account all details of each device. The advantages of this method have been proved with the successful design of two SIW waveguide topologies operating in (8{12)GHz and (10.7{12.75)GHz respectively for X-band and Ku-band applications employed in satellite communications. In order to validate the proposed method, a comparison is made between the FEM method implemented in Matlab and CST Microwave Studio R ∞ software. Agreements between the flnite element method data and the CST software results were achieved. The obtained results show the efiectiveness of this method to analyze such types of guides.

Choke flange-like structure for direct connection of cascaded substrate integrated waveguide components

Presented is the first device functionally equivalent to choke flanges used to connect rectangular waveguide components, intended for solderless cascading of substrate integrated waveguide (SIW) circuits without connectors or dedicated transitions to other kinds of transmission line. A line-up containing two SIW components connected by a novel choke-like pair has shown a return loss better than -14-dB inside a 5.4-6.4-GHz bandwidth. Uniform results were observed for all measurement conditions, including full electrical isolation between every part in the system required by some particular applications.

Review of substrate-integrated waveguide circuits and antennas

Substrate-integrated waveguide (SIW) technology represents an emerging and very promising candidate for the development of circuits and components operating in the microwave and millimetre-wave region. SIW structures are generally fabricated by using two rows of conducting cylinders or slots embedded in a dielectric substrate that connects two parallel metal plates, and permit the implementation of classical rectangular waveguide components in planar form, along with printed circuitry, active devices and antennas. This study aims to provide an overview of the recent advances in the modelling, design and technological implementation of SIW structures and components.

A novel technique for the direct determination of multimode equivalent circuit models for substrate integrated waveguide discontinuities

A novel technique is presented for the automatic, self-consistent and direct determination of wide-band lumped-element equivalent circuit models of substrate integrated waveguide discontinuities. This technique is based on the full-wave analysis of substrate integrated waveguide components by using the Boundary Integral-Resonant Mode Expansion method, which provides a generalized admittance matrix of the components in the form of a pole expansion in the frequency domain. This expression of the admittance matrix permits to directly identify the topology of a multimodal equivalent circuit and the values of its lumped elements, thus avoiding any initial guess or fitting procedure. The basic theory of the full-wave analysis method and the procedure for determining the equivalent circuit model are reported. The features of the proposed technique are detailed through the modeling of an iris-like discontinuity. Moreover, this technique is validated by modeling substrate integrated waveguide filters, whose frequency response is compared with numerical and experimental results. The proposed method can be adopted to obtain libraries of parametric models of substrate integrated waveguide discontinuities, which can be included in computer aided design tools. The multimodal parametric model of an iris-like discontinuity is presented and discussed. © 2008 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2009.

Investigations on the propagation characteristics of the substrate integrated waveguide based on the method of lines

A rigorous full-wave approach based on the method of lines (MoL) is presented to analyse the propagation characteristics of substrate integrated waveguides (SIWs), in which a generalised matrix eigenvalue equation is derived instead of the conventional transcend equation, greatly improving the computing efficiency. The use of an efficient Z-transform absorbing boundary condition (Z-ABC) further improved the accuracy of the calculated propagation constants. Finally, two empirical equations are proposed for the propagation constants of SIWs, which gives a simple but efficient tool in designing substrate integrated waveguide components.