Single-layer Circuit Research Articles

Design and simulation of Full-Subtractor based on Quantum-Dot cellular automata technology

A prospective replacement for CMOS technology is Quantum-dot Cellular Automata. It has advantages such as significant size reduction, fast switching speed, extremely high device density, and low energy usage. It is used to reduce the complexity of the digital circuit’ structure and to achieve a more efficient circuits. This paper focuses on the design of a Full-Subtractor. The number of cells used in the circuit structure is lowest because of the creativity in the design and the novel arrangement of quantum cells. As a result, the size of the circuit and the power loss have been reduced to a minimum compared to the circuits designed by the subtractor. The proposed structure is implemented in QCA technology as a single layer circuit. The suggested Full-Subtractor have been optimized in such a way that, compared to previous structures, has an improvement of 79.48% in cell number, 42.65% in delay, 48.65% in surface area and 68.96% in energy consumption. We utilize the QCADesigner and QCAPro tools to evaluate the performance of the proposed structure.

Low-Temperature Soldering of Surface Mount Devices on Screen-Printed Silver Tracks on Fabrics for Flexible Textile Hybrid Electronics.

The combination of flexible-printed substrates and conventional electronics leads to flexible hybrid electronics. When fabrics are used as flexible substrates, two kinds of problems arise. The first type is related to the printing of the tracks of the corresponding circuit. The second one concerns the incorporation of conventional electronic devices, such as integrated circuits, on the textile substrate. Regarding the printing of tracks, this work studies the optimal design parameters of screen-printed silver tracks on textiles focused on printing an electronic circuit on a textile substrate. Several patterns of different widths and gaps between tracks were tested in order to find the best design parameters for some footprint configurations. With respect to the incorporation of devices on textile substrates, the paper analyzes the soldering of surface mount devices on fabric substrates. Due to the substrate’s nature, low soldering temperatures must be used to avoid deformations or damage to the substrate caused by the higher temperatures used in conventional soldering. Several solder pastes used for low-temperature soldering are analyzed in terms of joint resistance and shear force application. The results obtained are satisfactory, demonstrating the viability of using flexible hybrid electronics with fabrics. As a practical result, a simple single-layer circuit was implemented to check the results of the research.

A Novel Two-Propagation-Modes Dual-Polarized Slotted-SIW Antenna for 5G and Sub-6GHz Services

A novel planar antenna for dual-linear-polarized applications, based on Substrate Integrated Waveguide (SIW) technology, and its dual-mode transceiver, acting as Orthomode Transceiver (OMT), are presented. TE10 and TE20 propagation modes are excited on the SIW to feed two orthogonal slots at the same time, operating at the same frequency band. Each slot produces the radiation according to the current distribution corresponding to their own mode without mutual interference. A dual-mode feeder and termination are used to excite a travelling wave in both modes, allowing the excitation and extraction of the propagation modes through the SIW on a single-layer circuit. In addition, a combination of 90°-hybrid circuits is designed in a single layer, to simplify the manufacture and assembly of the antenna, and acts as OMT by accomplishing the proper phase differences to create TE10 and TE20 at the same time and frequency on both sides of the SIW. As a result, a dual-beam and dual-polarized high-performance antenna is developed at sub-6GHz bands for 5G and other systems, such as Global-Coverage Satellites and Wi-Fi, through a combination of passive circuits to separate the orthogonal polarizations.

General Design Technique for High-Gain Traveling-Wave Endfire Antennas Using Periodic Arbitrary-Phase Loading Technique

This article proposes a general design technique for high-gain traveling-wave endfire antennas using a periodic arbitrary-phase loading technique. This work extends the periodic phase-reversal techniques reported in previous work to application scenarios where phase reversals are difficult to realize (e.g., single-layer circuits). It also relaxes the substrate permittivity requirement in phase-reversal techniques. To verify the proposed technique and theory, two design examples using different phases other than <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\pi $ </tex-math></inline-formula> are provided. Double-side parallel stripline and coplanar stripline are employed to provide vertical and horizontal polarizations, respectively. Double-side parallel stripline antenna achieves a maximum endfire gain of 15.6 dBi with vertical polarization. The coplanar-stripline antenna exhibits a maximum endfire gain of 16.6 dBi with horizontal polarization. The experimental results of these two examples validate the proposed technique.

On the Design of Ultrawideband Circuit Analog Absorber Based on Quasi-Single-Layer FSS

In this letter, an ultrawideband and single-layer circuit analog absorber with a low profile and small unit size is proposed. The absorber is composed of a Rogers 4003 dielectric with two square loop arrays, respectively, printed on the top and bottom, and a metal ground below. Lumped resistors are embedded on the four edges of the square-loop arrays to introduce resistance loss. Equivalent circuit, input impedance, and current distribution are then presented to provide great insight into the existence of three resonances and wideband. The absorber offers a fractional absorption bandwidth of 132.3% (4.91:1) with at least 10 dB reflection reduction. The thickness and the unit size are, respectively, reduced to $0.075\lambda _{L}$ (wavelength at the lowest frequency) and $0.13\lambda _{L}$ , leading to a good performance under oblique incidence. A good agreement between the calculated, simulated, and measured results validates the proposed design.

Nicking-Assisted Reactant Recycle To Implement Entropy-Driven DNA Circuit.

Synthetic catalytic DNA circuits are important signal amplification tools for molecular programming due to their robust and modular properties. In catalytic circuits, the reactant recycling operation is essential to facilitate continuous processes. Therefore, it is desirable to develop new methods for the recycling of reactants and to improve the recyclability in entropy-driven DNA circuit reactions. Here, we describe the implementation of a nicking-assisted recycling strategy for reactants in entropy-driven DNA circuits, in which duplex DNA waste products are able to revert into active components that could participate in the next reaction cycle. Both a single-layered circuit and multiple two-layered circuits of different designs were constructed and analyzed. During the reaction, the single-layered catalytic circuit can consume excess fuel DNA strands without depleting the gate components. The recycling of the two-layered circuits occurs during the fuel DNA digestion but not during the release of the downstream trigger. This strategy provides a simple yet versatile method for creating more efficient entropy-driven DNA circuits for molecular programming and synthetic biology.

Asymmetrical $4\times4$ Butler Matrix and its Application for Single Layer $8\times8$ Butler Matrix

The design procedure and measured results of a novel $4\times 4$ Butler matrix are presented in this paper. This asymmetrical structure provides fairly flexible phase outputs; therefore, the array radiation pattern can be rotated around the array normal axis. The structure of this modified Butler matrix is discussed in detail, and the explicit design formulas are derived to achieve the arbitrary main beams direction. Using the proposed design procedure, the Butler matrix can provide even broadside and endfire beams. In addition, this structure is employed to design two Butler matrices, which generate similar patterns as a conventional $8\times 8$ Butler matrix, using only single layer circuits with significantly lower sizes. Both structures are implemented for Wi-Fi frequency (2.45 GHz), and the measured results are presented. The first structure employs two asymmetrical $4\times 4$ Butler matrices, while the second one uses only one $4\times 4$ Butler matrix with single-pole double-throw (SPDT) switches added to select the proper constant phase shifts. The measured return loss, the average insertion loss, and the fractional bandwidth for the first structure are ≥23 dB, 6.6 dB, and 24%, respectively. These parameters for the second structure are ≥17 dB, 7.8 dB, and 20%, respectively. Moreover, the size reduction for the first and second structures compared to a conventional $8\times 8$ Butler matrix is about 50% and 80%, respectively.

High-Efficiency 3-D Antenna for 60-GHz Band

Design and measurement of a novel millimeter-wave antenna are presented. The radiating structure is based on a 3-D metallized molded plastic part which is soldered onto a thin, single-layer circuit board, and fed by a microstrip line of 50- $\Omega $ impedance. The 3-D structure is free of indentations and simple to manufacture. The −10 dB impedance bandwidth exceeds the 57–64 GHz license-exempt frequency band. Measurements show a gain of 5.8 dBi, half-power beamwidth of 85°– 90°, and indicate a high radiation efficiency of 90%.

On the Design of Single-Layer Circuit Analog Absorber Using Double-Square-Loop Array

A detailed study of a single-layer circuit analog absorber using double-square-loop array reveals that three resonances can be obtained within its operating frequency band. An equivalent circuit model is proposed to explain how these three resonances can be produced and its absorption bandwidth can be widened. Simple guidelines for the design of this double-square-loop absorber are then formulated. It is shown through measurements that the fractional bandwidth of 126.8% is realized for at least 10 dB reflectivity reduction under the normal incidence. Furthermore, the total thickness of the proposed design is only 0.088λL at the lowest operating frequency. A good agreement between simulated and measured results demonstrates the validity of our design.

Low-Profile Three-Arm Folded Dipole Antenna for UHF Band RFID Tags Mountable on Metallic Objects

A low-profile radio frequency identification (RFID) tag mountable on metallic objects is presented, which employs a multiple-arm folded dipole antenna. The proposed antenna is printed on a single-layer circuit board with an overall thickness of 1.5 mm not requiring any via or shorting plate. The presented configuration allows to match an RFID chip impedance with an imaginary part around - 400 Ω . A slightly modified version of the tag that allows an easy tuning of the frequency response is illustrated as well as a more compact tag obtained by allowing the use of vias. Prototypes for the RFID UHF band allocated in Europe have been fabricated, and measurements of the impedance and read range are provided.