Volume 73 (2022): Edizione 1 (February 2022)

Bit manipulation plays a significant role in high-speed digital signal processing (DSP) and data computing systems, and shift and rotation operations are crucial functions in it. In general, barrel shifters are used to perform these operations effectively. Nano magnetic logic circuits are among the promising beyond-CMOS alternative technologies for the design of high-speed circuits. Most of the existing circuits that have been developed using nano magnets are combinational circuits. In this work, a barrel shifter is implemented and realised using in-plane nano magnetic logic. The proposed design is the first of its kind nano magnetic logic circuit. The nano magnetic logic circuit implementation, layout generation, simulation, and validation were performed using the ToPoliNano and ModelSim tools. The logical equivalent design was synthesised and evaluated using the Synopsys Design Compiler tool. The proposed barrel shifter was realised using majority logic has 1769037 nano magnets with a boxing area of 481 × 13104 µm² and 3276 clock zones after optimisation with the Barycenter algorithm. The proposed barrel shifter realised using Boolean logic has 315276 nano magnets with a boxing area of 265 × 5028 µm² and 1257 clock zones after optimisation with the Barycenter algorithm. The proposed design results demonstrate that complex systems can be developed using nano magnetic logic by combining combinational and sequential circuits.

This paper develops an improved design of sliding mode control for high-order systems subjected to matched and mismatched disturbances. Unlike most of the literature implementations, that consider the mismatched disturbances as time vanishing disturbances with a known upper bound; the proposed approach works under time non-vanishing of both, the mismatched disturbances and their time derivatives. Furthermore, these disturbances and their time derivatives are bounded by an unknown constant. In contrast to the classical approaches that search for an approximation to the disturbance and then incorporates it into the controller to stabilise the system, the proposed scheme conducts the system output to achieve asymptotic convergence and this is without the need of any exact estimation of the disturbance. Two simulation examples are provided to illustrate the effectiveness of the proposed approach.

Self-shooting training is one of the fundamental criteria for success in basketball. Particularly, young players increase their performance with regular training. However, the training process becomes painful and time-consuming without a coach since the incorrect shooting posture causes missing shots, leading to reluctance. In this research, a self-shooting posture algorithm is developed to track the movement of basketball players and give them feedback about their position, angle, and basketball projectile trajectory information. The proposed algorithm uses computer vision techniques and Kalman filter to detect the best projectile trajectory using initial conditions such as acceleration due to gravity the initial velocity at the angle of launch having certain horizontal distance to the rim and the rim distance from the ground The acceleration of both gravity and air drag are altered by predefined parameters, including the drag coefficient basketball mass ball radius and silhouette area The proposed algorithm provides the shooting angle in real-time by placing the projectile angle on to the cropped image of the player posture and draws the projectile trajectory towards the basketball hoop According to the results, the players having a specified height can achieve the best shooting at the angle with air drag force. On the other hand, if there is no air resistance, the best shooting angle is deviated significantly. The other stats that are a total time of travel, maximum horizontal distance, maximum height and the time until the top are also given along with the results.

A multiple-input multiple-output (MIMO) antenna with a defective ground surface (DGS) is proposed for next-generation millimeter-wave communication. The designed antenna consists of a pair of mushroom shape radiating units with two square ring-loaded defected common ground plane. The antenna is printed on duroid-5880 high-frequency laminates (loss tangent 0.0009, relative permittivity 2.2). Significant bandwidth ranges from 31.6 GHz to 48.8 GHz (impedance bandwidth of 43.17%) is obtained during the investigation of the antenna. The introduced MIMO antenna exhibits a low mutual coupling (|S21|, |S12| < −20) dB with the incorporation of DGS. The antenna performance parameters defined as return loss, radiation pattern, gain, the radiation efficiency is examined. Many diversity parameters are also discussed in terms of mutual coupling, envelop correlation coefficient (ECC < 0.002), diversity gain (DG > 9.995), and channel capacity loss (CCL < 0.3 bits/sec/Hz) across the ultra-wide band (UWB) frequencies. Simulated results are verified by the measured results, and good agreement is observed between them. These distinguishable attributes with the simple configuration model the propound MIMO antenna suitable for millimeter-wave applications.

As a widely recognized electronic beam steering concept, frequency diverse array (FDA) radar is an effective and feasible solution to provide beam scanning ability in both angle as well as range dimension as a function of time. However, the conventional FDA radar employing progressive incremental frequency offsets across the array elements generates an S-shaped and range-angle coupled beampattern. As such, the FDA beampattern can be decoupled into range-angle dimensions by employing non-linear frequency offsets or using non-uniform arrays. Frequency offsets design has been extensively researched in recent years, whereas non-uniform arrays were given little attention so far. In this paper, we propose a novel FDA radar with a unified configuration of non-uniform linear array, and non-linear frequency offsets to achieve a high-resolution dot-shaped range-angle dependent beampattern. More specifically, the non-uniform inter-element spacing is calculated using the sigmoid function, and non-linear frequency offsets are generated by logistic map, and triangular window function. Simulation results clearly demonstrate the performance advantages of the proposed FDA radar in terms of beam width and side lobe levels.

PDMS (Polydimethylsiloxane) chips are increasingly important for the application of fluorescence measurements due to their auto-fluorescence free, excellent transparency, and biocompatibility. However, the design of PDMS microfluidic chips requires to fabricate plenty of molds for structure optimization, resulting in high cost. In the present, PDMS chips with nafion membrane were fabricated by simple and low-cost method for bull serum albumin (BSA) enrichment. To optimize the laser cutting and bonding parameters, simulation models were established using Bilinear Kinematic and Mooney-Rivlin models, respectively. The influence of laser power and cutting speed on the width and depth of the micro-channels was investigated. And the effect of bonding pressure on the deformation of PDMS micro-channel and stress distribution near the micro-channels was also analyzed. The leakage test and BSA enrichment demonstrated the practicability and feasibility of the present fabrication method in this work.

In the induction motor indirect vector control system, because of its physical limitations, the large step change in the speed command and/or load would eventually cause the so-called “integral windup phenomenon” which causes unexpected behavior of the system. To counteract this problem, an anti- windup generalized predictive speed control method is proposed by using the Youla parametrization. As first step, the design of an initial GPC controller based on its polynomial equivalent structure is required. Then, thanks to the Youla parametrization, this controller is retuned considering two specifications. The first is a frequency specification on the quadratic component of stator current response to the speed reference. And the second is a time domain constraint on the measured speed response to the speed reference. These constraints are formulated within a convex optimization framework. The simulation results proved the efficiency of the present design method.

In the paper, a pressure sensor and a humidity sensor are designed as supplementary components of a textile integrated waveguide (TIW) based on an artificial magnetic conductor (AMC) consisting of hexagonal elements. Thanks to AMC, sewing of electrically conductive side walls can be eliminated. Since operating in the stop-band of TIW, the sensors do not influence transmission parameters of TIW, and provide an additional functionality. For fabrication, a three-dimensional knitted fabric was used as a substrate and conductive surfaces were created from a self-adhesive copper foil. The sensors were simulated, manufactured and measured in the frequency range from 10 GHz to 12 GHz with a reasonable agreement. Since the designed components are sensitive on manufacturing tolerances, a higher measured insertion loss in TIW can be observed compared to simulations. Nevertheless, the insertion loss can be reduced when manufacturing accuracy is improved.

Silicone oil is a type of fluid with low viscosity, but it is not easy to form stable cone jet for electrohydrodynamic printing. In this paper, we proposed a new electrohydrodynamic printing method for patterns fabrication with this kind of low viscosity fluid. Dots array was first printed on the substrate at higher direct current voltage. Then by controlling the moving speed of the platform, the dots were connected into lines according to the fluidity of the silicone oil and its low surface tension. With the proposed method, the patterns with silicone oil can be successfully formed by electrohydrodynamic printing. In the experiment, the influence of main parameters including applied voltage, moving speed of substrate, distance from needle to substrate, and axial length of droplet on the quality of printed lines was studied. Finally, by optimizing the printing parameters, the silicone oil lines with width of 73 µm and low surface roughness were printed.

Substrate integrated waveguide (SIW) technology is widely known transmission line technology adapted for use in various types of microwave circuits. This article deals with the analysis and design of a phase shifter based on the SIW technology. With simulation and measurement results obtained from the phase shifter with using air holes inside the structure, a test circuit was designed and manufactured. Results show that a phase balance of less than 10° is achieved with the experimental setup. The return loss value is better than 15 dB for working frequency band 8.85 GHz − 9GHz. The main benefit of this work is the easy of implementation air holes inside the structure and also the easy of manufacture of the circuits for antenna arrays, where a certain number of identical circuits is usually needed.