A compact microstrip six-port reflectometer (SPR) with extended bandwidth is proposed in this paper. The design is based on using 16-dB multi-section coupled line directional couplers and a multi-section 3-dB Wilkinson power divider operating from 1 to 6 GHz. The proposed SPR employs only two calibration standards: a matched load and an open load. As compared to other dielectric substrates, fabricating the proposed SPR involves using a low-cost (FR4) substrate. A novel algorithm is also proposed to estimate the complex reflection coefficient over the frequency ranges at which the standard performance of the circuit components is not fully satisfied. The new algorithm is based on the circles’ intersection points, which have been derived from basic SPR equations, to estimate the complex reflection coefficient. To validate the SPR performance, a multiband microstrip patch antenna has been measured and the resulted reflection coefficient is compared with those obtained using a vector network analyzer (VNA). Results show that the proposed SPR provides a good estimation of the complex reflection coefficient within the frequency range of 1 GHz to 8 GHz. Owing to its compact size and ease of fabrication, the proposed reflectometer is suitable for various microwave broadband applications.
New biscarboxylato zwitterionic ligands, namely bis(N-carboxylatoethyl)-4,4 -dipyridinum) L1 and bis(Ncarboxylatopropyl)-)-4,4 -dipyridinum) L2, were synthesized from the reaction of 4,4 -dipyridine with 3-bromopropanoic acid and 4-bromobutanoic acid, respectively. The reaction of these ligands and the azido coligand with some metal ions resulted in the formation of polymeric complexes of general formulae [Cr2(Ln)(N3)4]Cl2·H2O and [M2(Ln)(N3)4] xH2O, where (M = Mn(II), Fe(II), Co(II), Ni(II), Cu(II), Zn(II) and Cd(II); n = 1, 2; x = 1, 1, 1, 1, 0, 1, and 1, respectively.) The oxygens of the carboxylato group are coordinated to the metal ion in a bidentate fashion. The mode of bonding and overall geometry of the complexes were determin
... Show MorePower-electronic converters are essential elements for the effective interconnection of renewable energy sources to the power grid, as well as to include energy storage units, vehicle charging stations, microgrids, etc. Converter models that provide an accurate representation of their wideband operation and interconnection with other active and passive grid components and systems are necessary for reliable steady state and transient analyses during normal or abnormal grid operating conditions. This paper introduces two Laplace domain-based approaches to model buck and boost DC-DC converters for electromagnetic transient studies. The first approach is an analytical one, where the converter is represented by a two-port admittance model via mo
... Show MoreLinear motor offers several features in many applications that require linear motion. Nevertheless, the presence of cogging force can deteriorate the thrust of a permanent magnet linear motor. Using several methodologies, a design of synchronous single sided linear iron-core motor was proposed. According to exact formulas with surface-mounted magnets and concentrated winding specification, which are relying on geometrical parameters. Two-dimensional performance analysis of the designed model and its multi-objective optimization were accomplished as a method to reduce the motor cogging force using MAXWELL ANSYS. The optimum model design results showed that the maximum force ripple was approximatrly reduced by 81.24%compared to the origina
... Show MoreIn recent years, arrays have been widely used in many applications, especially those applications that need high guidance, whether in military, medical, or other applications. Arrays are highly oriental, unlike single antennas. In this work, we analyze the effect of the insulating substrate insulation constant on the 2X2 microstrip patch antenna array at a frequency of 2.4 GHz, which is suitable for WLAN applications. CST Microwave Studio Version 2019 was used to design, simulate, and analyze the proposed model. The bar line feeding technique was used to feed the array. A set of mathematical relationships was used to calculate the dimensions of the array. We simulated and analyzed the array on three dielectric pillars: (FR-4) with
... Show MoreIn recent years, polymeric nanomaterials have attracted much attention to the fields of optoelectronics and energy storage due to their unique properties. In this study, to improve limitations, such as moderate conductivity and limited stability of polyaniline (PANi), PANi /WO3 nanocomposites with different amounts of tungsten trioxide nanoparticles (2,5, 5 and 10 wt%) were synthesized and investigated. The samples were prepared using the rotation coating method and evaluated in structural tests (XRD, FTIR, FESEM), optical (UV-Visible, PL) and photosensitivity. The results showed that the presence of WO3 caused a gradual decrease in the energy band gap from 3.04 eV in pure PANi to 2.37 eV in the 10 wt% sample, which led to facilitating elec
... Show MoreDeep submicron technologies continue to develop according to Moore’s law allowing hundreds of processing elements and memory modules to be integrated on a single chip forming multi/many-processor systems-on-chip (MPSoCs). Network on chip (NoC) arose as an interconnection for this large number of processing modules. However, the aggressive scaling of transistors makes NoC more vulnerable to both permanent and transient faults. Permanent faults persistently affect the circuit functionality from the time of their occurrence. The router represents the heart of the NoC. Thus, this research focuses on tolerating permanent faults in the router’s input buffer component, particularly the virtual channel state fields. These fields track packets f
... Show MoreA skip list data structure is really just a simulation of a binary search tree. Skip lists algorithm are simpler, faster and use less space. this data structure conceptually uses parallel sorted linked lists. Searching in a skip list is more difficult than searching in a regular sorted linked list. Because a skip list is a two dimensional data structure, it is implemented using a two dimensional network of nodes with four pointers. the implementation of the search, insert and delete operation taking a time of upto . The skip list could be modified to implement the order statistic operations of RANKand SEARCH BY RANK while maintaining the same expected time. Keywords:skip list , parallel linked list , randomized algorithm , rank.
A theoretical study to design a conformal microstrip antennas was introduced in this work. Conformal microstrip antennas define antennas which can be conformed to a certain shape or to any curved surface. It is used in high-speed trains, aircraft, defense and navigation systems, landing gear and various communications systems, as well as in body wearable. Conformal antennas have some advantages such as a wider-angle coverage compared to flat antennas and low radar cross-sectional (RCS) and they are suitable for using in Radome. The main disadvantage of these antennas is the narrow bandwidth. The FDTD method is extremely useful in simulating complicated structures because it allows for direct integration of Maxwell's equations depending o
... Show MoreThis research includes theoretical and evaluation design of a polarizer filter of high transmission in the near IR region of (900-1200nm) for different incidence angles to obtain a long wave and short wave pass filter using analytical calculations. Results refer to a new configuration design in fewer layers than used in previous studies in the long wave pass at incidence angles (45o,50o,55o). Adopted Hafnium dioxide (HfO2) and Magnesium fluoride (MgF2) as coating material at design wavelength (933nm), the study also included design short wave pass polarizer by using the same coating material.