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Wide bandgap semiconductors enable high voltage (10 kV and more) switches. As a consequence, new packaging solutions are required to prepare the ground for such devices. The metallized ceramic substrate is a well-known and established technology for voltages up to 3.3kV, but it exhibits some weaknesses at higher voltages: due to its manufacturing process, the profile of the metallization is sharp...
The capabilities of multi-layer substrates to reduce mutual coupling between closely spaced (0.3–0.5 of the free-space wavelength) patch antenna elements in antenna arrays are investigated. The inhomogeneity is created in vertical direction by inserting relatively higher and lower permittivity layers on top of each other and to the appropriate positions inside the single-layer, homogeneous substrate...
A low-cost, easy-to-fabricate paper-based capacitance sensor with inkjet printed interdigitated electrodes is presented. The sensor enables measurements of the dielectric properties of electrode free polymer films, a quick technique for assessing the insulating quality of polymer sheets. We demonstrate the suitability of the sensor for moisture and vapor measurements, permitting direct operation of...
In this paper, a reconfigurable graphene transmission array is proposed for the generation of vortex radio waves at THz. By perforating the substrate with holes of various diameters, different values of effective permittivity are obtained. The transmission coefficient can be adjusted by changing the chemical potential of graphene. With the excitation of planar wave, the phase-compensation of corresponding...
The tapered aperture distribution of the substrate integrated horn antenna always limits its aperture efficiency and widens the antenna beam width. Therefore, the integrated H-plane horn has rarely been considered for the applications where fan-beam types of radiation pattern are required. Here, the amplitude distribution of the integrated horn aperture has been improved to be almost uniform by the...
A new technique for reducing the substrate permittivity in a Substrate Integrated Waveguide (SIW) structure is presented, consisting of removing a centered rectangular box of substrate dielectric material, which increases the equivalent waveguide impedance. This technique can be applied to the implementation of high-impedance SIW sections (perforated regions) sandwitched between low-impedance sections...
The paper presents CAD models for computing dispersive and conductor thickness based line parameters of semi-elliptical/circular cylindrical coplanar striplines (CPS) on single-layered dielectric substrates. Analysis of the non-planar CPS has been performed using conformal mapping technique (CMT). The developed models are verified and validated for wide range of line geometries from 1 GHz–60 GHz....
Electromagnetic modeling of sensing of stochastic distributions of nanometer-sized particles usually requires a large number of calculations to correctly obtain the average response of a sensor. Here, we present an alternative method, which utilizes a gradient effective permittivity model based on the classical Maxwell-Garnett mixing formula. In our model the nanoparticle layer is homogenized into...
Design of unit cell of Microstrip Reflectarray Antenna (MRA) is one of important parameter. Using infinite array approach method, resonant element of MRA is observed in unit cell environment. The reflection phase curve helps to compare the different commercially available dielectric materials.
Flexible 2.5 cm × 2.5 cm PZT thin films on polyimide substrate were successfully obtained through a release and transfer process developed in this work. The released films not only functioned, but had superior properties compared to films grown on silicon wafers. This approach to flexible piezoelectric devices provides opportunities for sensors, transducers, and energy harvesters.
Printed electronics become more and more relevant for applications in wearable electronics and sensors. Inkjet printing of silver nano-particles can be done at very low cost with a reasonably high precision and conductivity. In this paper, we investigate flexible patch antennas for wireless chip-to-chip communication scenarios, rapidly prototyped using an inkjet printing process. A patch antenna with...
The present article describes the investigations, performed in order to determine some dielectric characteristics of anodic aluminum oxide (AAO), obtained by electrochemical anodization process. The AAO layer is grown directly on aluminum substrates, considered as suitable carriers for multi-chip modules (MCM). Test samples for measurements of the dielectric permittivity and loss tangent were elaborated...
An experimental method was introduced for understanding the exact relationships among polarization, coercive field, and electric field across the ferroelectric layer. They characterized the ferroelectric properties closed inside the metal/ferroelectric/insulator/semiconductor gate stacks. Using the method, we found that N2-dominant-gas annealing process was effective for improving the ferroelectricity...
The paper presents generalization of micromechanical control principle for number of microwave devices, such as tunable phase shifters and resonator based filters. Starting with one dimensional dielectric discontinuity model, control principle is propagated to microstrip line devices and dielectric resonators. Maximum possible tuning range is discussed along with accompanying insertion loss.
This study presents the results on the feasibility of a resonant planar chemical capacitive sensor in the microwave frequency range suitable for gas detection and for wireless communications applications. The objective is to develop a low cost ultra-sensitive sensor that can be integrated into a real time multi-sensing platform. The first demonstrators target the detection of harmful gases such as...
In this work, the first broadband dielectric characterization of African trypanosome parasites from 0.2 to 2.5 THz is presented as a foundation for future sensor applications in the mm- and THz-wave regime. After demonstrating detectability, the complex permittivity of a 5 micrometer thick parasite film is extracted directly from measurements of a terahertz time domain spectrometry setup using a chain...
A new topology of stepped impedance filters in substrate integrated waveguide (SIW) technology is presented in this paper. The filters are based on the reduction of the effective dielectric permittivity on certain waveguide sections which are below cutoff in the pass-band of the filter. Two different techniques for reducing the substrate permittivity have been analyzed and compared. In the first one,...
The aim of this paper is to study graphene plasmonics for THz applications. The range of absorbance of electromagnetic waves on a graphene monolayer is investigated to understand the plasmonic behaviour of graphene on patterned SiO2 substrate. Simulation results show that absorption range and intensity gets altered according to the graphene doping level, periodicity of grating and dielectric media...
Availability of fast yet reliable replacement models (also referred to as surrogates) is essential to reduce the computational cost of antenna design process. Unfortunately, conventional approximation (or data-driven) modeling is not well suited for modeling of highly nonlinear responses of antenna structures, especially for larger number of geometry parameters. The latter is due to the so-called...
This paper presents the experience in designing LTCC antennas operated in F-band (90–140 GHz). A few examined structures are presented and their electrical parameters dependencies on LTCC technology limitations are shown. The paper is focused on two main aspects: the first one is related to the quality of multi-layered structures and the second one to the properties of metallization, which has a big...
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