Y. Cassivi

Bio: Y. Cassivi is an academic researcher from École Normale Supérieure. The author has contributed to research in topics: Waveguide filter & Microstrip. The author has an hindex of 5, co-authored 7 publications receiving 1349 citations.

Dispersion characteristics of substrate integrated rectangular waveguide

Abstract: Dispersion properties of the substrate integrated rectangular waveguide (SIRW) are rigorously obtained using the BI-RME method combined with the Floquet's theorem. Our analysis shows that the SIRW basically has the same guided-wave characteristics as the conventional rectangular waveguide. Empirical equations are derived from the calculated dispersion curves in order to estimate the cutoff frequency of the first two dominant modes of the SIRW To validate the analysis results, an SIRW guide was designed and measured. Very good agreements between the experimental and theoretical results were obtained.

The substrate integrated circuits - a new concept for high-frequency electronics and optoelectronics

Abstract: A new generation of high-frequency integrated circuits is presented, which is called substrate integrated circuits (SICs). Current state-of-the-art of circuit design and implementation platforms based on this new concept are reviewed and discussed in detail. Different possibilities and numerous advantages of the SICs are shown for microwave, millimeter-wave and optoelectronics applications. Practical examples are illustrated with theoretical and experimental results for substrate integrated waveguide (SIW), substrate integrated slab waveguide (SISW) and substrate integrated nonradiating dielectric (SINRD) guide circuits. Future research and development trends are also discussed with reference to low-cost innovative design of millimeter-wave and optoelectronic integrated circuits.

Design considerations of engraved NRD guide for millimeter-wave integrated circuits

Abstract: Practical construction of nonradiative dielectric (NRD) guide components such as filters, junctions, or hybrid planar NRD-guide circuits is rather difficult because of the tedious alignment and tolerance requirement of various separate NRD-guide elements. To overcome this hurdle, we present a new scheme called the engraved NRD guide (ENRD). This ENRD guide is an NRD guide whose outline is machined out of a single dielectric block, thereby eliminating the alignment constraint, and allowing a better precision for physical design, realization, and integrity of the overall circuit. Design considerations and procedures of the ENRD guide are studied and discussed in this paper, which suggest the predominance of gap dimension in obtaining a quasi-nonradiative condition with similar propagation properties as a normal NRD guide. It also shows that the amount of dielectric material left in support of the whole structure alignment could greatly affect the leakage level of the guide. An ENRD-guide 90/spl deg/ bend and filter were designed and measured. Investigation of the ENRD-guide filter leads to the characterization of an evanescent LSM/sub 10/ mode in the air gap region between the resonators necessary for reducing its insertion loss.

Engraved NRD-guide for millimeter-wave integrated circuits

Abstract: Practical realization of NRD (non-radiative dielectric)-guide components such as filter, T-junction or hybrid planar NRD-guide circuit is rather complicated because of the alignment requirement of various elements of the structure. We present a new platform called "Engraved NRD-guide (ENRD)". In this proposed structure, only the outline of NRD-guide is machined out of a dielectric block. It eliminates the alignment constraint and allows for a more precision design/realization and also a better physical integrity of the overall circuit. Using the ENRD-guide, a microstrip-to-NRD-guide transition and a filter were realized and measured, confirming its feasibility. It is believed that this technique will ease the fabrication of NRD-based millimeter-wave transceiver that may involve multiple NRD components.

Hybrid planar NRD-guide magic-tee junction

Abstract: A new magic-tee circuit is proposed and developed, which is based on the hybrid integration technology of a planar and nonradiative dielectric (NRD) guide. The magic-tee junction combines an NRD-guide T-junction with a microstrip T-junction. Furthermore, LSM/sub 10/-mode radiators are introduced in the magic-tee circuit to reduce its resonance problem. Measured results show that an isolation of 20 dB can easily be achieved between the sum and difference ports.

Guided-wave and leakage characteristics of substrate integrated waveguide

Abstract: The substrate integrated waveguide (SIW) technique makes it possible that a complete circuit including planar circuitry, transitions, and rectangular waveguides are fabricated in planar form using a standard printed circuit board or other planar processing techniques. In this paper, guided wave and modes characteristics of such an SIW periodic structure are studied in detail for the first time. A numerical multimode calibration procedure is proposed and developed with a commercial software package on the basis of a full-wave finite-element method for the accurate extraction of complex propagation constants of the SIW structure. Two different lengths of the SIW are numerically simulated under multimode excitation. By means of our proposed technique, the complex propagation constant of each SIW mode can accurately be extracted and the electromagnetic bandstop phenomena of periodic structures are also investigated. Experiments are made to validate our proposed technique. Simple design rules are provided and discussed.

Review of substrate-integrated waveguide circuits and antennas

Abstract: 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.

Accurate modeling, wave mechanisms, and design considerations of a substrate integrated waveguide

Abstract: A new method of analysis is presented in this paper for the determination of complex propagation constants in substrate integrated waveguides (SIWs) This method makes use of the concept of surface impedance to model the rows of conducting cylinders, and the proposed model is then solved by combining a method of moments and a transverse resonance procedure The proposed method is further applied to extract results in terms of parametric curves and graphs which demonstrate fundamental and interesting wave guidance and leakage properties of this type of periodic waveguide Useful design rules are extracted from this analysis, suggesting that appropriate design parameters and regions should be carefully selected for practical applications In addition, comprehensive review and comparisons with published results are also presented to show the performance and accuracy of the proposed modeling technique Practical measurements of fabricated samples with different levels of loss have confirmed the accuracy of this new method and validity of design rules

The substrate integrated circuits - a new concept for high-frequency electronics and optoelectronics

Abstract: A new generation of high-frequency integrated circuits is presented, which is called substrate integrated circuits (SICs). Current state-of-the-art of circuit design and implementation platforms based on this new concept are reviewed and discussed in detail. Different possibilities and numerous advantages of the SICs are shown for microwave, millimeter-wave and optoelectronics applications. Practical examples are illustrated with theoretical and experimental results for substrate integrated waveguide (SIW), substrate integrated slab waveguide (SISW) and substrate integrated nonradiating dielectric (SINRD) guide circuits. Future research and development trends are also discussed with reference to low-cost innovative design of millimeter-wave and optoelectronic integrated circuits.

Simulation and experiment on SIW slot array antennas

Abstract: By etching longitudinal slots on the top metallic surface of the substrate integrated waveguide (SIW), an integrated slot-array antenna is proposed in this letter. The whole antenna and feeding system are fabricated on a single substrate, which takes the advantage of small size, low profile, and low cost, etc. The design process and experimental results of a four-by-four SIW slot array antenna at X-band are presented.