This paper presents a novel approach to design a miniaturized ultra-wideband (UWB) microstrip bandpass filter (BPF) with triple notched bands using a Multimode Resonator (MMR). The MMR is integrated with folded high-impedance interdigital coupled-line structures, enabling the filter to achieve a UWB characteristic while offering independent control over the introduced notched bands to prevent interference with other operating systems. Additionally, the adoption of folded interdigital coupled-line structures significantly reduces the overall dimensions of the filter. The LC equivalent circuits and transfer function of the proposed MMR are extracted to analyze the behavior of the filter. To validate the design, a fabricated prototype of the proposed filter with triple notched bands at 5.4, 8.1, and 10.1 GHz, featuring attenuations exceeding -22 dB, is presented. The measured results demonstrate that the designed filter provides a passband ranging from 4.2 to 12 GHz, along with a wide rejection bandwidth of up to 20 GHz.

This paper presents a compact topology for implementing multiband bandpass filters. The design uses interconnected Multimode Resonators (MMRs) and multi-level impedance structures to achieve a specific frequency response. This approach simplifies the design of quadruple bandpass filters for 4G and 5G applications. Since line widths cannot be adjusted post-construction, resonance positions require tuning. To evaluate the filter design process, a prototype incorporating MMRs was designed, manufactured, and analyzed, demonstrating close alignment between analytical predictions and experimental measurements, despite no simulation or optimization being performed during the design phase, except for result verification.Additionally, a design criterion is established to facilitate the rapid and reliable synthesis of multiband responses by varying only a few geometrical parameters of the MMRs. A simulation of this structure was conducted using CST software to confirm the proposed theory's accuracy. A reverse-biased varactor diode, which functions as a capacitor with specific admittance, is utilized to provide the necessary tuning capability. The paper also highlights the impact of the varactor diode's admittance on resonance location adjustments. To validate the design, the authors present a fabricated prototype of the proposed filter, which features quarter bands at 1.8, 2.1, 2.7, and 3.4 GHz, achieving an attenuations greater than -15 dB. The quarter band filter is primarily used in wireless telecommunications networks. Due to their specialized design, these filters can process multiple frequency bands simultaneously, enhancing communication quality and increasing network capacity in crowded and interference-prone environments.

Multimode contour integral method is one of methods in analysis and design of H-plane waveguide circuits. In this method, the effect of higher order modes excited by discontinuities in waveguide structure is considered. This causes to approve the accuracy of method in analysis or design of complex waveguide circuits.In this article, the Multimode contour integral method is used to determine the properties of dielectric Resonators (DRs) such as resonant frequency and dielectric constant. Thus, it is not necessary to optimize or tuning the designed DR filter. Also the accuracy goes high. The accuracy of method is validated by comparison of results with those reported in literatures.

This paper deals with the design consideration and performance results for low power low noise self-matched as well as an inductive-matched SiGe amplifier developed for the GSM/DCS/WCDMA multi-band cellular systems.The self-matched amplifier is based on the current reuse concept, and accommodates an active balun. On the other hand, the inductive-matched amplifier is a single-stage common emitter circuit with inductive on-chip matching. Both amplifiers have internal bias circuits. These amplifiers consume 5.0mA and 6.0mA at 3V to respectively provide a power gain of higher than 18dB and 13dB, a noise figure lower than 4dB, and an IIP3 higher than –16dBm and -4dBm, over 0.9-2.2GHz. With such a low current consumption, the developed amplifiers can be a candidate for low-power Multimode mobile terminal applications.

In this paper, the motion capability of wheeled mobile robot is increased by providing a new structure. Due to the special design, converting a two-wheeled robot to a four-wheeled robot is possible in the proposed multi-mode robot. This design has the ability to simultaneously and interchangeably provide locomotion and manipulation capability in motion on uneven terrain. Unlike most other mobile robot designs that have a separate manipulator arm module attached on top of the mobile platform, the central axis in this design can manipulate like a robotic arm. The robot midpoint as an end-effector is a passive joint. The part which could carry the guidance and visual equipments follows the height control, easily and without a new actuator. The basic requirement of stability and acceptable performance could be guaranteed through this simple, novel design. Finally, the simulation is used to study the robot’s enhanced mobility characteristics through animations of different trajectories for end-effector on uneven terrain.

The proposed structure is a closed-loop dual-band filtering antenna, in which the antenna and the Resonator are combined together. The filtering antenna consists of two triangular Resonators and a rectangular loop micro-strip antenna. The surface structure of a Rogers RO-4003 substrate with dielectric (εr) equal to 3.55 and insulation loss tangent (tgδ) equal to 0.0027 and a thickness of 32 mm is placed at frequencies of 3.4, 5.28 and 8 5.5 GHz, which indicates a return loss below 10 dB. This structure is suitable for Wi-Max and the fifth generation mobile communication network, and the filter antenna proposed for these applications has a suitable bandwidth and radiation pattern in its resonance frequencies. The design and analysis of the structure has been done using HFSS software. To confirm the correctness of the simulation results, a laboratory sample of the proposed filtering antenna is made and it shows the correctness of the measured values of the design and simulation

Antivibration isolators are made from both crystalizing rubbers and non-crystalizing rubbers. Their fatigue resistance is different. Although the recently developed effective tensile stress criterionhas been validated in crystalizing rubber under different R ratios (the ratio between the minimum stress value and the maximum stress value), its application to non-crystalizing rubbers has never been verified. In this study, this criterion was tested against a non-crystalizing rubber using two types of samples under R ≥ 0 conditions for 168 fatigue cases with different loading modes. Considering that a shape change may also cause fatigue damage, a new shear stress criterion was derived and subsequently tested. The unified S-N curves (2×102 - 3×106 cycles) obtained have achieved narrow bands with a scatter factor of 1.35 with a correlation coefficient R2 ≥  0.90 using these two criteria. This potential novel approach could be more effective than the current methods, which use fitting functions with adjustable parameters determined from an additional experiment. This offers greater choices and flexibility to engineers in their selection of the most appropriate suited criteria for their design in anti-vibration applications.

Resource constrained project scheduling problem is one of the most important issues in project planning and management. The objective function of this problem is to minimize the completion time of a project. When there is budget constraint or high risk for investment, using the criteria such as cash flows is so important. The development of computer systems and processors makes it possible to take more assumptions into modeling to obtain robust optimal solution. Recent research has been conducted on Multimode resource constrained project scheduling problem with preemptive activities (P-MRCPSP). Assuming preemption of activities causes the model to approach the real-world problems in project scheduling. This assumption may occur due to factors such as equipment failure and shortage of resources. In most of the previous studies, the change in mode of activities was not possible after the discontinuation. In this paper, it is assumed that each activity can continue in various modes of operation after a stop. The developed model aims to minimize project completion time and maximize cash flow of the project, simultaneously. Two algorithms, i. e. Simulated Annealing (SA) and Multiple Objective Particle Swarm Optimization (MOPSO) have been developed to solve the proposed model. The obtained results of these two algorithms show that SA algorithm has the better performance.