Current Issue : April-June Volume : 2024 Issue Number : 2 Articles : 5 Articles
This paper focuses on the problem of high-performance streaming random number generation in the range of uniform and normal distributions in FPGAs. Our work is focused on lightweight implementation, suitable for a wide range of FPGAs. First, we review the existing types of random generation modules. Next, in this paper we present the construction of the designed generator. We divide it into two sections: Stream Uniform Numbers Generator Implementation and Cumulative Distribution-Based Stream Gaussian Generator. Each design step was verified in the scope of the quality of the output data, especially regarding the produced distributions. The results obtained are compared with existing solutions. We mainly consider resource utilization and throughput. We also add our quality factor, which is an effective utilization of FPGAs. Despite quality results, our modules were implemented using a high-level synthesis language (C/C++), contrary to typical hardware description level (HDL) approaches. It provides the opportunity to implement the proposed algorithms on CPUs. It was tested with positive results, thus highlighting the versatility of the solution that is unavailable in terms of HDL implementations. Our designed generators were confirmed to stand out for their satisfactory performance while occupying low logical resources....
In this paper, a low-cost resin-coated commercial-photo-paper substrate is used to design a printed reconfigurable multiband antenna. The two PIN diodes are used mainly to redistribute the surface current that provides reconfigurable properties to the proposed antenna. The antenna size of 40 mm × 40 mm × 0.44 mm with a partial ground, covers wireless and mobile bands ranging from 1.91 GHz to 6.75 GHz. The parametric analysis is performed to achieve optimized design parameters of the antenna. The U-shaped and C-shaped emitters are meant to function at 2.4 GHz and 5.9 GHz, respectively, while the primary emitter is designed to operate at 3.5 GHz. The proposed antenna achieved peak gain and radiation efficiency of 3.4 dBi and 90%, respectively. Simulated and measured results of the reflection coefficient, radiation pattern, gain, and efficiency show that the antenna design is in favorable agreement. Since the proposed antenna achieved wideband (1.91–6.75 GHz) using PIN diode configuration, using this technique the need for numerous electronic components to provide multiband frequency is avoided....
We present an optically reconfigurable multifunctional metamaterial with switchable wideband absorption and transmission across the THz frequency range. The reconfigurability is achieved by introducing optically active silicon into the resonator of the metamaterial unit which could be effectively modulated through external electrical pumping. When the silicon conductivity reaches 50,000 S/m, the metamaterial shows significant absorption of electromagnetic waves ranging from 3.1 to 10 THz. By reducing the applied external pump power and decreasing the silicon conductivity to 150 S/m, the proposed metamaterial exhibits transmission of the incident waves at 5.12 THz with a transmission coefficient of 61%. The proposed optically reconfigurable metamaterial has the advantages of simple structure, wideband absorption, and switchable between absorption and transmission modes, showing potential applications in stealth, communication, or radar systems....
Weight Fair Queuing is an ideal scheduling algorithm to guarantee the bandwidth of different queues according to their configured Weights when the switching nodes of the network are congested. Many of the switching nodes based on FPGA in the current network support four physical ports or hundreds of virtual ports. Massive logic and storage resources would be consumed if each port implemented a WFQ scheduler. This paper proposes a Queue-Group-Based WFQ Scheduler (QGWFQS), which can support WFQ scheduling across multiple ports through the reuse of tag calculation and encoding circuits. We also propose a novel finish tag calculation algorithm to accommodate the variation in the link rate of each port. The remainder of integer division is also taken into account, which makes the bandwidth allocation fairer. Experimental results show that the proposed scheduler supports up to 512 ports, with 32 queues allocated on each individual port. The scheduler has the capability to operate at 200 MHz and the total scheduling capacity reaches 200 Mpps....
Recently, reconfigurable coding metasurfaces have attracted extensive attention due to their dynamic and flexible manipulation of electromagnetic (EM) waves, making them an effective solution to connect physical reality and information science. Nevertheless, most previously reported reconfigurable metasurfaces suffer from limited applications, as they solely possess either phase or amplitude modulation. In this article, we propose a reconfigurable coding metasurface that can regulate both phase and amplitude response independently. In the field of the metasurface, the phase response can tailor the wavefronts, and the amplitude response can adjust the redistribution of the energy of the EM waves. Specifically, by integrating a PIN diode into the meta-atom and controlling its bias voltage, the reflection phase can be switched between two opposite phases with a phase difference of about 180◦, and the reflection amplitude can be manipulated from 0.02 to 0.98 continuously at 11 GHz. The unit element consists of simple multi-layer structures, reducing its production cost and processing difficulty. By loading 1-bit phase code and multi-bit amplitude code to each unit element severally, this metasurface can modulate the distribution of reflected EM waves in two-dimensional (2-D) space while simultaneously suppressing the sidelobes for any quantity of scattered beams over a wide operating band ranging from 10.5 to 11.5 GHz. This metasurface exhibits promising potential for manipulating the distribution of EM wave energy and shaping of EM beams, which can be expected to facilitate wireless communication technology....
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