Mehdi Nosrati

Compact MEMS-Based Ultrawide-Band CPW Band-Pass Filters With Single/Double Tunable Notch-Bands

In this paper, novel ultrawide-band (UWB) band-pass filters with single and double tunable notch-bands are described. To the best of our knowledge, this is the first MEMS-based UWB filter reported with double tunable notch-bands. In this design, a new configuration of μ-strip coupled lines integrated with the MEMS capacitor is developed and used for tuning. The proposed structure is analyzed by considering the LC equivalent circuit of the MEMS capacitor and it is shown that an extra transmission zero (notch-band) is realized at its resonance. Each notch-band frequency can be independently tuned up to 1 GHz using MEMS capacitors actuation, while the filter performance across its ultrawide pass-band remains unchanged. The proposed filter is suitable for UWB applications when flexible interference blockage is required.

A novel ultra wideband (UWB) filter with double tunable notch-bands using MEMS capacitors

This paper presents a novel UWB filter with double tunable notch bands on coplanar technology. Each notch-band frequency can be independently tuned using MEMS capacitors while the filter performance across its ultra-wide pass band remains unchanged. The measured results indicate up to 1GHz independent tuning range for each notch frequency. To our knowledge, this is the first UWB filter reported with double tunable notch bands. In addition, a high impedance resonator has been incorporated and a size reduction of up to 66% has been achieved compared to its conventional half wavelength counter parts. The proposed filter is suitable for ultra wide band applications when flexible interference blockage is required.

A novel compact dual-wideband BPF with multiple transmission zeros and super wide upper stopband

In this article, a novel miniaturised dual-wideband bandpass filter (DWB-BPF) based on two different resonators including a quasi-spiral loaded multiple-mode resonator (QSL-MMR) and L-shaped transmission line (LS-TL) is presented. At the first step, in order to design a single wideband BPF filter with controllable transmission zeros near the centre frequency, the open circuit impedance parameter of quasi-spiral loaded resonator Z21 is determined in terms of ABCD matrix. Then an equivalent circuit model of the proposed structure is derived and the impedance characteristic and electrical length of LS-TLs to achieve a DWB-BPF with excellent selectivity are calculated through even- and odd-mode analysis. The proposed filter possesses both compact and simple structure as well as two wide passbands with fractional bandwidth (FBW) of 70% and 22.8% for its first and second passbands, respectively. The proposed technique creates two transmission zeros at the lower and upper stopbands of each passband resulting in a very sharp roll-off accompanied by a wide stopband. Notably, the circuit size is reduced and the bandwidth is enhanced in comparison with its conventional counterparts. The theoretical performance of the filter is verified by the experimental one where a good agreement is reported between them.

A novel compact dual band-notched band-pass filter using multiple-mode resonators

In this paper, realization of a novel extremely compact dual notch-bands (DNBs) ultra-wideband band-pass filter (UWB BPF) is investigated using combination of μ-strip multiple-mode resonators (MMRs) loaded with high-impedance open stubs without any via-hole or complicated multi-layer technology to facilitate the design process of this type of BPF. Here is also elaborated the realization of four transmission zeros (TZs) both at the lower and upper sides of the passband and other ones within the passband to demonstrate DNBs UWB BPF. Additionally, the estimates are presented to demonstrate TZs curves in terms of frequency. Furthermore, a novel compact DNBs UWB BPF is designed and demonstrated where a size reduction of around 49.6% and 77.7% is reported in comparison with the most recent conventional ones.

Substrate Integrated Waveguide L-Shaped Iris for Realization of Transmission Zero and Evanescent-Mode Pole

This paper investigates L-shaped iris (LSI) embedded in substrate integrated waveguide (SIW) structures. A lumped element equivalent circuit is utilized to thoroughly discuss the iris behavior in a wide frequency band. This structure has one more degree of freedom and design parameter compared with the conventional iris structures; therefore, it enables design flexibility with enhanced performance. The LSI is utilized to realize a two-pole evanescent-mode filter with an enhanced stopband and a dual-band filter combining evanescent and ordinary modes excitation. Moreover, a prescribed filtering function is demonstrated using the lumped element analysis not only including evanescent-mode pole, but also close-in transmission zero. The proposed LSI promises to substitute the conventional posts in (SIW) filter design.

Magnetic current and new modifications of Maxwells equations

M equations are the main foundation of the current communication technology; however, they are still incomplete with some ambiguities and unknown parameters. Magnetic current is apparently the main missing part of these equations [1]. In this talk, we resolve to revise these equations and the conventional definitions of the terms and parameters from the beginning merely based on logical theory to justify all measurements so far. These revisions will be initiated by modifying Bohr’s Model and physical differentiations of magnetic and electrical fluxes to justify all electromagnetic phenomena under a consistent umbrella. Consequently, we can theoretically present a rational illustration of magnetic current and amend the contradictions and inconsistencies in the current models and theory of electromagnetic waves. As given in current Maxwell’s equations given in (1)-(2), these equations are not balanced where the right sides of these equations consist of two Equ. (1) and three components Equ.(2).The weighted mean appears when a physical quantity is measured by different methods in different laboratories, producing different xi results. It is the case of determination of physical constants (as Nuclear Data analysis), International Comparisons of radioactive sources and still others. (The formula 1) with wi absolute weights and pirelative weights. A relation exists (2) with σithe individual standard deviations including possible systematic uncertainty as which do not affect the logical (1). Formula (2) is obtained with some complicated calculations in [1], [2], [3].T topic of spin dynamics in solid-state nuclear magnetic resonance opens a way to an infinite number of suggestions. In this abstract, we present the power and the salient features of the promising theoretical approach called Floquet–Magnus expansion that is helpful to describe the time evolution of the spin system at all times in nuclear magnetic resonance. Interesting applications of the Floquet–Magnus expansion approaches are illustrated by simple solid-state NMR experiments. However, it is very important to remember that the method of Floquet-Magnus expansion had recently found new major areas of applications such as topological materials. Researchers, dealing with those new applications, are not usually acquainted with the achievements of the magnetic resonance theory, where those methods were developed more than thirty years ago. They repeat the same mistakes that were made when the methods of spin dynamics and thermodynamics were developed in the past. This presentation is very useful not only for the NMR and physics communities but for the new communities in several younger fields. Solid-state NMR is definitely a timely topic or area of research, and not many papers on the theory of spin dynamics are available in the literature of NMR.E and geometrical structure of neutral and charged iron clusters Fen, Fen, and Fen (n = 2-20) will be discussed. Computational results will be compared to experimental data, in particular, to the recent data obtained from the magnetic moment measurements of Fen +. We consider iron cluster oxides, single Fe atom oxides FeOn for n up to 18, and FeXn superhalogens. We present the results of computational simulations of gas-phase interactions between small iron clusters and OH, N2, CO, NO, O2, and H2O. Competition between surface chemisorption and cage formation in Fe12O12 clusters will be discussed. The magnetic quenching found for Fe12O12 will be qualitatively explained using the natural bond orbital analysis for Fe2O2. Special attention will be paid to the structural patterns of carbon chemisorbed on the surface of a ground-state Fe13 cluster.

Wafer-level waveguide filter realization using simplied 3D fabricaiton process

This paper discusses a new technique to realize a wafer-level band-pass waveguide filter. The proposed waveguide takes advantage of a newly developed 3D fabrication process that enables realization of waveguide structures on wafer-level. The waveguide filter can be constructed on top of the substrate, making it independent of the substrate material. The proposed structure is suitable for millimeter-waves applications.