Luca Perregrini

Bio: Luca Perregrini is an academic researcher from University of Pavia. The author has contributed to research in topics: Waveguide filter & Microstrip. The author has an hindex of 33, co-authored 291 publications receiving 4360 citations. Previous affiliations of Luca Perregrini include University of Perugia.

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.

Dielectric Properties Characterization From 0.5 to 50 GHz of Breast Cancer Tissues

Abstract: Knowledge of the dielectric properties of human tissues is important for several biomedical applications, including imaging and hyperthermia treatment, as well as for determining safety thresholds in policy making. Breast tissues, both normal and tumorous, are of particular interest because of the medical and social impact of breast cancers. While experimental data is available up to 20 GHz, for higher frequencies, this information is missing, or has been extrapolated from models based on lower-frequency data. Emerging technologies and applications in the millimeter-wave region would benefit from experimental data that bridge this gap. This paper presents the characterization of dielectric properties of breast tissues for the frequency range from 0.5 to 50 GHz. Cole–Cole models are derived for normal and tumorous tissues based on experimental measurements on more than 220 tissue samples obtained at surgery ( ex vivo ) from a population exceeding 50 patients, covering a wide span of normal and tumorous tissues, from patients ranging in age from 28 to 85 years, with a time from excision to measurements under 3.5 h. This paper also presents a comprehensive analysis of the differences between normal and tumorous breast tissues at different frequencies in terms of sensitivity and specificity.

A Novel Substrate Integrated Coaxial Line (SICL) for Wide-Band Applications

Abstract: A novel substrate integrated coaxial line (SICL) is presented and experimentally verified in this paper This structure exhibits unimodal operation over a wide frequency band, is shielded and not dispersive, can be fabricated by using simple, low-cost thin?film process, and can be easily integrated with active devices Moreover, the same technology results particularly suitable to realize passive components for wideband applications The design of a Lange coupler with operation bandwidth of 66%, to be used in a Multi-port Impulse Radio for Ultra Wide Band applications, is reported

Modeling of Conductor, Dielectric, and Radiation Losses in Substrate Integrated Waveguide by the Boundary Integral-Resonant Mode Expansion Method

Abstract: This paper presents the modeling of lossy substrate integrated waveguide interconnects and components by using the boundary integral-resonant mode expansion method. The extension of the numerical technique to account for conductor, dielectric and radiation losses is discussed. Moreover, a systematic investigation of the different contributions of loss and their dependence on some geometrical parameters is performed in the case of interconnects and components, aiming at minimizing the losses. The physical explanation of the different effects is also provided. Finally, the validity of the equivalent waveguide concept is extended to the case of lossy interconnects and components.

Current and Future Research Trends in Substrate Integrated Waveguide Technology

Abstract: Substrate Integrated Waveguide (SIW) tech- nology is the most promising candidate for the implemen- tation of millimeter-wave (mm-wave) integrated circuits and systems for the next decade. Based on planar dielectric substrates with top and bottom metal layers perforated with metalized holes, SIW structures offer a compact, low loss, flexible, and cost-effective solution for integrating active circuits, passive components and radiating elements on the same substrate. This paper presents an overview of the current status and future trends of academic and in- dustrial research on SIW technology. The historical devel- opment of SIW components and circuits is briefly outlined, and the current research topics are discussed: they include the development of numerical techniques for the modeling and design of SIW components, the investigation of novel compact and broadband interconnects, the determination of design solutions for loss minimization. Future research trends are also discussed: they mainly aim at the imple- mentation of SIW components at higher frequency (60-350 GHz) and the integration of complete Systems-on-Substrate (SoS).

I and i

Abstract: There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality. Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

Terahertz spectroscopy and imaging – Modern techniques and applications

Abstract: Over the past three decades a new spectroscopic technique with unique possibilities has emerged. Based on coherent and time-resolved detection of the electric field of ultrashort radiation bursts in the far-infrared, this technique has become known as terahertz time-domain spectroscopy (THz-TDS). In this review article the authors describe the technique in its various implementations for static and time-resolved spectroscopy, and illustrate the performance of the technique with recent examples from solid-state physics and physical chemistry as well as aqueous chemistry. Examples from other fields of research, where THz spectroscopic techniques have proven to be useful research tools, and the potential for industrial applications of THz spectroscopic and imaging techniques are discussed.

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.

Single-substrate integration technique of planar circuits and waveguide filters

Abstract: The integrated planar technique has been considered as a reliable candidate for low-cost mass production of millimeter-wave circuits and systems. This paper presents new concepts that allow for a complete integration of planar circuits and waveguide filters synthesized on a single substrate by means of metallized post (or via-hole) arrays. Analysis of the synthesized integrated waveguide and design criteria are presented for the post pitch and diameter. A filter design method derived from a synthesis technique using inductive post is presented. An experimental three-pole Chebyshev filter having 1-dB insertion loss and return loss better than 17 dB is demonstrated. Integrating such planar and nonplanar circuits on a substrate can significantly reduce size, weight, and cost, and greatly enhance manufacturing repeatability and reliability.