Switch Matrices Research Articles

Entropy Analysis of FPGA Interconnect and Switch Matrices for Physical Unclonable Functions

Random variations in microelectronic circuit structures represent the source of entropy for physical unclonable functions (PUFs). In this paper, we investigate delay variations that occur through the routing network and switch matrices of a field-programmable gate array (FPGA). The delay variations are isolated from other components of the programmable logic, e.g., look-up tables (LUTs), flip-flops (FFs), etc., using a feature of Xilinx FPGAs called dynamic partial reconfiguration (DPR). A set of partial designs is created to fix the placement of a time-to-digital converter (TDC) and supporting infrastructure to enable the path delays through the target interconnect and switch matrices to be extracted by subtracting out common-mode delay components. Delay variations are analyzed in the different levels of routing resources available within FPGAs, i.e., local routing and across-chip routing. Data are collected from a set of Xilinx Zynq 7010 devices, and a statistical analysis of within-die variations in delay through a set of the randomly-generated and hand-crafted interconnects is presented.

Compact, Scalable, Fast‐Response Multimode 2 × 2 Optical Switch Based on Inverse Design

AbstractMode‐division multiplexing (MDM) introduces a new dimension to on‐chip optical interconnection, where the multimode optical switch is one of the core components. However, researchers are still struggling to reduce the chip size and response time, despite great efforts being made. Here, a compact, scalable, fast‐response multimode 2 × 2 switch supporting four modes is demonstrated based on the specific inverse design. The device consists of two multimode 2 × 2 CB couplers (including mode converters, multimode interference couplers, and crossings) and a thermo‐optic (TO) phase shifter. It achieves extinction ratios exceeding 15 dB for all modes at the central wavelength of 1.55 µm. All the fundamental components are designed by an improved general shape optimization method, realizing a compact size and a larger manufacturing tolerance (±20 nm). Besides, a hydrogen‐doped indium oxide microheater is introduced as a TO phase shifter to achieve a fast response (≈3.5 µs in average) for all modes. This solution provides an effective avenue toward large‐scale multimode optical switch matrices for the future MDM systems.

Dynamic reconfiguration of photovoltaic array for minimizing mismatch loss

Mismatch conditions owing to different internal and external factors, such as partial shading and module defects, can directly degrade the power generation of distributed photovoltaic arrays. In this study, a reconfiguration solution called multiple switching matrices is proposed to mitigate mismatch losses for any size of the total-cross-tied photovoltaic array. In the proposed solution, the photovoltaic array is divided into several sub-arrays using switching matrices. The current and voltage values of each module are collected by the electric measurement sensors and sent to the control unit, and the proposed reconfiguration solution can be implemented by controlling switching matrices. The performance of the proposed reconfiguration solution is evaluated extensively for a range of mismatched conditions, including partial shading patterns and partial shading with random failure patterns. The P–V and I–V characteristics are analyzed by comparison with the existing sudoku-based arrangement and the conventional total-cross-tied interconnection topology. Moreover, three main parameters and standard deviations of the maximum power point for each pattern, are considered. The numerical results confirm the effectiveness and flexibility of the proposed reconfiguration solution for optimizing photovoltaic array generation under various mismatch conditions.

Optimal Adjacent Output Phase Difference Assignments in One-Dimensional Parallel Switching Matrices With Four Beams

Optimal Adjacent Output Phase Difference Assignments in One-Dimensional Parallel Switching Matrices With Four Beams

Two‐plane waveguide coupler with arbitrary coupling ratios in the H‐plane and E‐plane directions

AbstractA comprehensive theoretical analysis of two‐plane waveguide coupler with arbitrary coupling ratios in the H‐plane and E‐plane directions is provided and a design of the two‐plane coupler with coupling ratio in the H‐plane direction and coupling ratio in the E‐plane direction is reported. The analysis of the two‐plane waveguide coupler is fully refined and accomplished by the authors. To realise an arbitrary and different coupling ratio in the two directions, it is crucial to specifically constrain the transition phase of the quarter model of the two‐plane coupler for different boundaries as necessitated by mode polarity. A prototype of the proposed two‐plane coupler is manufactured and measured to verify the concept. Its performance is observed from 27.0 to 29.5 GHz (8.85% fractional bandwidth). The measurement results are basically in accord with the simulation results, demonstrating the reliability of the theoretical analysis. Finally, samples of designed conventional H‐plane and E‐plane couplers are provided, cascading of which can realise the same functionality as the proposed two‐plane coupler. Compared with one‐plane couplers, the two‐plane coupler reported realises overall miniaturisation rates in terms of length and volume around 58.4% and 50.1%, respectively. According to the demonstration and verification of the two‐plane couplers having arbitrary coupling ratios, the employment of the two‐plane couplers to replace the conventional one‐plane couplers to realise miniaturisation of 2‐D beam switching matrices will be promoted in future applications.

Review of 2 × 2 Silicon Photonic Switches

With the advent of 5G, artificial intelligence (AI), Internet of Things (IoT), cloud computing, Internet plus, and so on, data traffic is exploding and higher requirements are put forward for information transmission and switching. Traditional switching requires optical/electrical/optical conversions, which brings additional power consumption and requires the deployment of large amounts of cooling equipment. This increases the cost and complexity of the system. Moreover, limited by the electronic bottleneck, electrical switching will suffer from many problems such as bandwidth, delay, crosstalk, and so on, with the continuous reduction in device footprint. Optical switching does not require optical/electrical/optical conversions and has lower power consumption, larger capacity, and lower cost. Silicon photonic switches received much attention because of their compatibility with the complementary metal-oxide-semiconductor (CMOS) process and are anticipated to be potential candidates to replace electrical switches in many applications such as data center and telecommunication networks. 2 × 2 silicon photonic switches are the basic components to build the large-scale optical switching matrices. Thus, this review article mainly focuses on the principle and state of the art of 2 × 2 silicon photonic switches, including electro-optic switches, thermo-optic switches, and nonvolatile silicon photonic switches assisted by phase-change materials.

Modular thermoelectric generation arrays reconfiguration under heterogeneous temperature distribution via improved cooperation search algorithm: Modelling, design and HIL validation

• ICSA based modular TEG arrays reconfiguration is presented. • Enhanced exploration operator and discretization are incorporated into ICSA. • Solution optimization program reduces possible unnecessary switching actions. • Feasibility of the proposed method are validated under two TEG arrays. • An RTLAB platform based real-time hardware-in-the-loop test has been carried out. • Maximum output power is increased by 146.45 W under asymmetric TEG array. This paper innovatively proposes a modular thermoelectric generation (TEG) arrays reconfiguration technique based on an improved cooperation search algorithm (ICSA), which aims to mitigate the troublesome effects of heterogeneous temperature distribution (HTD) conditions and fully exploit their power generation potential. Firstly, the original TEG array is divided into three blocks, upon which only two switch matrices are required to implement various reconfiguration, while its number of switches and construction costs can be significantly reduced. Secondly, the ratio of output power and voltage range (namely voltage imbalance factor (VIF)) between TEG columns is regarded as a fitness function to simultaneously maximize output power and minimize voltage imbalance. Furthermore, in order to solve this model, ICSA is designed to effectively and efficiently seek the global optimum. Meanwhile, three traditional discrete meta-heuristic algorithms are employed for comparison (e.g., genetic algorithm (GA), particle swarm optimization (PSO), and simulated annealing (SA) algorithm). Besides, to validate the problem formulation and solver design, both symmetric ( 15 × 15 ) and asymmetric ( 15 × 20 ) TEG arrays are tested under three typical HTD conditions, i.e., outer, centre, and random. Lastly, simulation results on MATLAB verify that ICSA can rapidly smooth the output power curves and dramatically enhance generation efficiency of TEG arrays. Specifically, the maximum output power can be increased at most by 93.77 W with a decrease of 164.02 V of VIF under symmetric case, and 146.45 W with a decrease of 111.92 V of VIF under asymmetric scenario, respectively.

Nonvolatile multi-level adjustable optical switch based on the phase change material.

For the advantages of the faster computation speed and lower energy consumption, all-optical computation has attracted great attention compared with the traditional electric computation method. Optical switches are the critical elementary units of optical computation devices. However, the traditional optical switches have two shortcomings, expending the outside energy to keep the switch state and the weak multi-level adjustable ability, which greatly restrict the realization of the large-scale photonic integrated circuits and optical spiking neural networks. In this paper, we use a subwavelength grating slot-ridge (SWGSR) waveguides on the silicon platform to design a nonvolatile multi-level adjustable optical switch based on the phase change material Ge2Sb2Te5 (GST). Changing the phase state of GST can modulate the transmission of the optical switch, and the change of the optical transmittance of the optical switch is about 70%, which is much higher than that of previous optical switches. As no static power is required to maintain the phase state, it can find promising applications in optical switch matrices and reconfigurable optical spiking neural networks.

Special assignments of adjacent output phase differences per input ports in generalized one-dimensional parallel switching matrices

Special assignments of adjacent output phase differences per input ports in generalized one-dimensional parallel switching matrices

Photovoltaic array reconfiguration under partial shading conditions for maximum power extraction: A state-of-the-art review and new solution method

Non-uniform irradiance due to partial shading conditions (PSCs) reduces the power delivered by the photovoltaic (PV) cell. The output power reduction in the PV arrays directly depends on the shading pattern and type of array configuration which is selected. So far, many dynamic and static reconfiguration methods have been used for maximum power point tracking under PSCs in the PV arrays. However, most conventional methods suffer from some major problems such as the need for additional equipment and sensors, complex wiring, the use of expensive sensors, production of complex switching matrices, high costs, and inability to reconfigure PV arrays with very small, large, and non-square sizes. Accordingly, this paper, after reviewing the dynamic and static PV array reconfiguration methods, presents a novel static-based technique called 8-Queen's for reconfiguring the PV modules corresponding to the Total-Cross-Tied (TCT) inter-connection PV array. The 8-Queen's technique has a great ability to apply on high dimensions and rectangular shapes PV arrays and is based on the movement of 8 queens on the chessboard so that none of the queens can attack the others. The effectiveness of the suggested method is expressed by implementing it on 7 cases of the TCT PV array in different sizes and various PSCs. In a comparative scenario, the performance and effectiveness of the proposed 8-Queen's technique are evaluated compared to other conventional methods. Indicators of global maximum power point (GMPP), fill factor, power efficiency, and mismatch losses evaluate the results of the employed methods. The evaluation of results represents the effectiveness of the 8-Queen's technique compared to other used methods. In addition, the performance evaluation of the proposed technique in real-world PV arrays is performed by modeling a sample PV array taking into account measurement errors. The results in this step also show that the proposed technique can also provide acceptable performance for solving problems related to maximum power point tracking under PSCs in PV systems.

One-Body Two-Dimensional Switching Matrices With a Triangular Lattice of Beams

This letter presents a numerical design method of one-body two-dimensional (2-D) switching matrices with a triangular lattice of an arbitrary number of beams in each of horizontal and vertical directions, improving the overlap between the beams in a 2-D multiple-beam coverage. With the proposed matrix configuration, the minimum number of cascaded units consisting of a mix of 1-D and 2-D couplers and phase shifters is found to be smaller than that of the conventional cascade of 1-D matrices when the number of beams is larger than three in either of horizontal or vertical directions. The proposed solution is of interest for millimeter-wave applications requiring spatial diversity.

Frequency-Reconfigurable SP4T Switch With Plaid Metal Transistors and Forward Body Biasing for Enhanced RON × COFF Characteristics

A frequency-reconfigurable SP4T switch is presented, in which <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${R}_{\text {ON}} \times {C}_{\text {OFF}}$ </tex-math></inline-formula> characteristics of switch transistors are enhanced with plaid metal transistors and forward body biasing. Plaid metal transistors (PMT) with forward body bias (FBB) are used for all of the transistors to enhance the FoM. The plaid patterned metal accesses of a transistor for the source and drain decrease the extrinsic resistance and capacitance. FBB increases the overdrive voltage of a transistor and decreases the on-resistance. The SP4T switch includes main switch matrices that route an input signal to four-outputs, a switched inductor (SI) network, and a mode-selection switch. The SI network connected through the mode-selection switch resonates out the off-capacitances of the main switch matrices at RF in the RF mode. The SP4T switch operates without the SI network in DC mode. The SP4T switch is implemented in a 28-nm FDSOI CMOS process. The core area occupies 0.2 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> . The switch shows less than 2 dB insertion loss from DC to 4.4 GHz in the DC mode and from 4.4 to 5.3 GHz in the RF mode, where isolations are more than 16.8 dB and 18 dB, respectively.

Generalized One-Dimensional Parallel Switching Matrices With an Arbitrary Number of Beams

This paper introduces a novel family of one-dimensional switching matrices, also known as beamforming networks (BFNs), which can be sized for an arbitrary number of beams. It also describes the associated numerical design method, supported by several design examples. The concept is further validated with a full-wave model of a generic 5 × 5 switching matrix designed at 76 GHz. The proposed matrices are obtained by cascading units consisting of a two-way coupler and a phase shifter in a parallel configuration, providing theoretically lossless operation as a direct consequence of the orthogonal BFN topology and equalized path lengths, expected to benefit the frequency bandwidth. The design method is general, also including the configurations equivalent to Butler matrices when the number of beams is a power of two. The obtained planar matrix designs combine some benefits of the well-known Butler and Nolen matrices, namely the parallel topology and the arbitrary number of beams. The minimum number of cascaded units required by the proposed topology, also corresponding to the number of layers, is found to be <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$N$</tex-math></inline-formula> , where <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$N$</tex-math></inline-formula> is the number of beams, which is less than the number of cascaded units for the corresponding “parallel” Nolen matrix, for <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$N$</tex-math></inline-formula> larger than three, thus providing a reduction in the number of layers of up to 38% for an 8-beam matrix. This reduction is close to the theoretical upper boundary of 50%, reached for large values of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$N$</tex-math></inline-formula> . This significant reduction is expected to have a positive impact on RF performance, and in particular insertion losses, as well as amplitude and phase dispersion over the operating band. Interestingly, the proposed switching matrix configuration reduces to a standard Butler matrix when the number of beams is equal to 4, and demonstrates a reduction in the number of layers of 20% over the corresponding planar Butler matrix for a design with 8 beams. The proposed matrix configuration is a promising solution for the design of low-cost single-layer beam-switching matrices.

Design of reconfigurable on-chip wireless interconnections through Optical Phased Arrays.

In this paper we report the design of a device allowing on-chip optical wireless interconnections, based on transmitting and receiving Optical Phased Arrays (OPA). The proposed device aims at realizing high-bandwidth and power-efficient reconfigurable connections between multiple nodes, e.g. chiplets stacked onto a common silicon interposer in 2.5D manycore systems. The communication through an optical wireless switch is a completely novel approach to overcome the bottleneck of wired communication and to provide flexibility in the network topology configuration. We report the OPA design criteria as well as the results of three-dimensional Finite Difference Time Domain (FDTD) simulations. We exploit the in-plane radiation of simple taper antennas to implement 1×N and N × N switching matrices. The effect of the multipath propagation in the on-chip multi-layered medium is also taken into account.

Phase change material enabled 2 × 2 silicon nonvolatile optical switch.

Recently, large-scale photonic integrated circuits have seen rapid development. Optical switches are the elementary units used to realize optical routers and processors. However, the high static power and large footprint of silicon electro-optic and thermo-optic switches are becoming an obstacle for further scaling and high-density integration. In this Letter, we demonstrate a 2×2 nonvolatile silicon Mach-Zehnder optical switch enabled by low-loss phase change material Sb2S3. Changing the phase state of Sb2S3 can switch the optical transmission between the bar and cross paths. As no static power is required to maintain the phase state, it can find promising applications in optical switch matrices and reconfigurable optical circuits.

Scalable Two-Mode 3-Port and 4-Port Mode Insensitive Silicon Photonic Switches

We propose and experimentally demonstrate a novel design approach for scalable 3-port and 4-port mode insensitive multimode switching matrices for the first two quasi-transverse electric (TE) modes. The mode insensitive phase shifter ensures less power consumption for simultaneous multimode signal transmission in a mode division multiplexing (MDM) network. At 1550 nm, the 3-port switch exhibits approximately 2.6 dB and 3.3 dB insertion loss for the longest path with a crosstalk of at most 10 dB and 8 dB over a bandwidth of 40 nm (1530 nm to 1570 nm) for <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${\mathrm {TE}}_{\mathrm {0}}$ </tex-math></inline-formula> and <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${\mathrm {TE}}_{\mathrm {1}}$ </tex-math></inline-formula> modes, respectively. The insertion loss measured for the 4-port switch is approximately 2.7 dB and 3.6 dB at 1550 nm with a corresponding crosstalk less than 8 dB for the two TE modes, respectively. The payload transmission is also performed using both 10 Gb/s non-return-to-zero (NRZ) and 14.0625 Gbaud 4-level pulse-amplitude modulation (PAM4) pseudorandom binary sequence (PRBS)-31 data signal to analyze the performance of the switches. Clear open eyes are observed for both single-mode and simultaneous two-mode transmissions. The low insertion loss, low intermodal crosstalk over a large optical bandwidth, and the clear open eye validate the scalability of the proposed switches for larger port count and higher-order modes.

Multifold behavior of the information transmission by the quantum 3-switch

We uncover new behaviors of the transmission of information by three quantum channels in superposition of causal orders subject to some level of noise. We find that the transmission can exhibit three different behaviors as the level of noise is varied. This multifold behavior can be explained by the different equivalence classes of quantum switch matrices related to specific combinations of causal orders. We classify these matrices using their characteristic polynomials and matrix invariants, and we calculate analytical expressions for the Holevo information in three representative cases. Our results are a step forward to understand and harness quantum control of causal orders with different levels of noise. We also study the Holevo information as function of a continuous order parameter and analyze transitions at integer values.

Behavior Analysis of Brand Loyalists and Brand Switcher in 5-Star Accommodation Services in Medan City

A brand is a fundamental part of the marketing strategy in influencing purchase interest. A person’s buying ability will influence a customer to choose the product they want. In addition, higher competitiveness among hotels will create more awareness to maintain customer satisfaction and turn it into customer loyalty as the main target of their marketing. In connection with achieving customer loyalty, hotels must study the factors influencing customers to become loyal or switch from the hotel brand. A brand can be measured through brand equity which consists of a set of assets and liabilities of the Brand associated with the name and symbol of the Brand that can be given to consumers. Important and measurable components in forming brand equity include brand awareness, brand association, perceived quality, and brand loyalty. This study examines the variables that make the difference between loyalists and customers who switch hotel brands. The data used were taken from 42 respondents spread across the International Departure Terminal of Kualanamu Airport. The research method used is descriptive with a quantitative approach. The data were analyzed using the discriminant analysis method through the SPSS 12.0 program. And other limitations for this research are 5-Star Hotels and Chain International in Medan. Discriminant analysis shows that one factor requiring search variation distinguishes between brand loyalists and brand switchers. The Brand switching matrices show that all hotels serving consumers in Medan have low customer loyalty. The ratio between brand loyalists and brand switchers was 1:9, which means that only one person is loyal to one brand out of 10 consumers of accommodation services. The rest are types of consumers who like to switch to other brands.

Fine resolution delay tuning method to improve the linearity of an unbalanced time‐to‐digital converter on a Xilinx FPGA

In this study, a method for fine adjustment of Xilinx field programmable gate array (FPGA) routing delays is proposed and applied to improve the linearity of an unbalanced multi-measurement time-to-digital converter (TDC). The delay control method increases load capacitances of interconnect points of switch matrices by small amounts using additional connections to unused interconnects in the FPGA fabric. The novel delay control method uses the tool command language (TCL) scripting feature available in the Xilinx Vivado tool to automatically add wires into a fully placed and routed design. A total of 61 additional wires were successfully and automatically added to reduce the differential and integral non-linearities of the target TDC from 0.51 and −0.54 LSB to 0.05 and 0.06 LSB, respectively (reduction factors of 10.2 and 9) for an LSB equal to 333 ps.

Optimization of high-channel count, switch matrices for multinuclear, high-field MRI.

Modern magnetic resonance imaging systems are equipped with a large number of receive connectors in order to optimally support a large field-of-view and/or high acceleration in parallel imaging using high-channel count, phased array coils. Given that the MR system is equipped with a limited number of digitizing receivers and in order to support operation of multinuclear coil arrays, these connectors need to be flexibly routed to the receiver outside the RF shielded examination room. However, for a number of practical, economic and safety reasons, it is better to only route a subset of the connectors. This is usually accomplished with the use of switch matrices. These exist in a variety of topologies and differ in routing flexibility and technological implementation. A highly flexible implementation is a crossbar topology that allows to any one input to be routed to any one output and can use single PIN diodes as active elements. However, in this configuration, long open-ended transmission lines can potentially remain connected to the signal path leading to high transmission losses. Thus, especially for high-field systems compensation mechanisms are required to remove the effects of open-ended transmission line stubs. The selection of a limited number of lumped element reactance values to compensate for the for the effect of transmission line stubs in large-scale switch matrices capable of supporting multi-nuclear operation is non-trivial and is a combinatorial problem of high order. Here, we demonstrate the use of metaheuristic approaches to optimize the circuit design of these matrices that additionally carry out the optimization of distances between the parallel transmission lines. For a matrix with 128 inputs and 64 outputs a realization is proposed that displays a worst-case insertion loss of 3.8 dB.