Dimensions Of Coupler Research Articles

Design guideline of capacitive power transfer system to achieve targeted output power

Power transfer capability of the capacitive power transfer (CPT) system is dependent on the dimensions of capacitive coupler, which should be correctly designed to meet the required amount of output power. This paper presents a guideline to design the conductive plates used in CPT system to achieve a targeted output power. For a given operating frequency, resonant inductance, DC input voltage, load resistance, and the air gap between plates, the required cross-sectional area of conductive plates is obtained using this guideline. It has been guided through the design procedure which is explained in detail. A step-by-step guide to design a 5-watts CPT system is demonstrated as a design example. The proposed design guideline is verified by the experiment which shows the closeness between measured and targeted output power. Design error is obtained as low as 3.6 percent.

Design Methodology of a Three Coil IPT System With Parameters Identification for EVs

The benefits of intermediate couplers (IC) in inductive power transfer (IPT) systems are well documented in the literature. However, the lack of guideline rules makes the selection process of the passive components and operation mode difficult. This paper presents an iterative design methodology based on the equivalent mathematical model of the system to determine the optimal magnetic coupler (MC) dimensions and resonant tanks parameters that operates the system in a quasi constant current mode. It was found that the transconductance function of a series-series (SS) with an intermediate coupler exhibits a quasi-load independent characteristic when the reflected reactance from the receiver side is null. The design methodology then combines the self and mutual coupling profiles of the MC, obtained from a finite element analysis (FEA) tool, with the system specifications and constraints to find all possible solutions. A set of selection metrics are proposed to identify the optimal solution. This work also presents an identification method of the load and mutual inductances based only in the information available from the transmitter side. The proposed method uses the steady-state equations and does not require any form of communication to the receiver side. An experimental prototype was built and assembled in a converted combustion vehicle with efficiency of 89$%.

A New Coupler Critical Dimensions (CCD) Method for Linkage Mechanisms Mobility Analysis

A new Coupler Critical Dimensions (CCD) approach to define mobility criteria (crank, rocker conditions, or existence) for linkage mechanisms has been presented in this paper. The idea is to analyze the extreme lengths of a mechanism coupler link when the mechanism is on the extreme of its existence or changing its mobility condition. The method leads a set of expressions of the constant mechanism parameters that can be used to define the exact dimensional limits of the coupler link in the mechanism. These expressions present sufficient and necessary dimensional conditions for the mechanism existence and become a turning point to change its mobility from crank to a rocker and vice versa. At the boundaries of the coupler dimensions, the mechanism reaches its the change-point configuration where the mechanism may switch either from one work function to another or from existence to non-existence. The method has been successfully applied to the planar 4R, spatial RSSR, and planar multiloop linkage mechanisms. The obtained results prove the effectiveness and accuracy of the method in defining the limits of the mechanism rotatability conditions or existence in general.

Compact Dual Band Ring Coupler Using Miniaturized Metamaterial Left-Handed Impedance Inverters

A compact 3-dB dual band ring coupler is designed, fabricated and tested. The coupler consists of three identical miniaturized Left-Handed (LH) impedance inverter transmission lines (TLs) and a dual one. The general principle of using LH TLs' duality to reduce the size of a dual band ring coupler is explained in detail, showing the equivalent lumped element circuits and the designing relations. A numerical example is considered for the duality analysis and the results are used to obtain a size reduction for both the coupler's dimensions and the number of utilized components. Other arbitrary coupling levels (1 dB and 5 dB) and frequency ratios are investigated and the results of simulations show very good results, proving the validity of the general principle of using LH transmission line's duality. The 3-dB coupler is implemented in microstrip technology and using high-quality lumped components. It works at two arbitrary frequencies, 1.1 GHz and 2.5 GHz, respectively with similar performances. The overall dimension of the proposed coupler is 0.07λ×0.07λ for a wavelength, λ computed at 1.1 GHz. The measured results are in good agreement with the predicted ones for both frequencies, having the return loss and isolation loss better than 33 dB, whereas keeping the insertion and coupling losses at around 3.5 dB in both frequency bands. The phase imbalance at the output ports is less than 1.5°, when the difference and sum ports are excited.

Modeling two-qubit Grover’s algorithm implementation in a linear optical chip

This paper introduces a model of Grover’s algorithm suitable for implementation in a linear photonic chip. We compare two known realizations of its main components, two-qubit CZ gates, in order to define optimal chip architecture. The algorithm operation is simulated considering directional coupler imperfection influence on the scheme parameters. We also determined tolerance boundaries for distortions of the coupler dimensions.

A Millimeter-Wave Miniature Branch-Line Coupler in 22-nm CMOS Technology

A 60-GHz innovative quadrature branch-line coupler is proposed in this letter. The device was implemented in a 22-nm CMOS process, from global foundries. The proposed design merges two miniaturization techniques. On the one hand, slow-wave microstrip (SW-MS) lines based on bed of nails are demonstrated in CMOS technology for the first time. On the other hand, the two quarter-wavelength MS line sections required for the branch-line coupler implementation are realized using the SW-MS transmission line configurations with different form factors. As a result, the achieved miniaturization versus electrical performance is very good as compared to the state-of-the-art. Design insights addressing the coupler dimensions and losses are discussed. The experimental assessment shows an adequate frequency response with amplitude and phase imbalance of 0.8 dB and 1.8° at 60 GHz, respectively. The measured insertion loss is 2.35 dB at 60 GHz and the return loss is better than 15 dB at any port (from 54 to 66 GHz). The isolation is better than 15 dB (from 51 to 68 GHz). The overall size of the coupler is 0.3 mm $\times $ 0.22 mm, which is equivalent to $0.06 \cdot \lambda _{0} \times 0.044 \cdot {\lambda }_{0}$ , at 60 GHz.

Two Methods for Miniaturization of Stub Quadrature Couplers

Two circuit-topological methods for reducing the overall dimensions of stub quadrature coupler (SQCs) are considered. The essence of the presented methods lies in replacing quarter-wave stubs with low-pass filters and artificial transmission lines (ATLs). It is shown that, using these methods, it is possible to reduce dimensions of two-stub and five-stub coupler by 71.9%. The design and experimental characteristics are presented; it is found out that the band of operating frequencies of compact SQCs is 1.4 times less than the bandwidth of conventional coupler and the imbalance of the power division coefficient increases.

Extremely compact microstrip branch‐line coupler with a novel fold structure

AbstractAn extremely compact 900‐MHz microstrip branch‐line coupler with a novel fold structure was proposed. A novel profile of the fold structure prevented the overlapping of stub lines to minimize the branch‐line coupler dimensions. The measured insertion, isolation, and return losses of the proposed coupler were 3.94, 38.2, and 23.9 dB, respectively, and the measured phase difference between the two output ports was 90° ± 0.1°. Compared with the optimized area of a conventional branch‐line coupler, the optimized area of the proposed coupler was reduced to 14.9%. Notably, the proposed coupler can be easily integrated with wireless communication systems because it can be implemented using standard printed circuit board etching processes without any lumped elements, bonding wires, or via holes.

Reconfigurable 3/6 dB Novel Branch Line Coupler

In this paper, a new idea of reconfigurable 3/6 dB branch line coupler is proposed. The proposed coupler is tuned through a simple open and short circuit at the coupler’s branches’ edges. At the short edges case, a 3 dB branch line coupler is obtained. In this case, the coupler’s branches are considered as microstrip transmission lines with 0.3 mm slot width which is etched in each coupler’s branch. At the open edges case, the coupler’s branches are considered as asymmetric coupled microstrip lines. In this case, a 6 dB branch line coupler is obtained. Both CST and IE3D simulators are used to optimize the reconfigurable 3/6 dB branch line coupler dimensions. As a prototypes, two BLCs are designed, analyzed and tested at the “on” and “off” states at 2.5 GHz. The measured S-parameters confirm the proposed concept of the reconfigurable 3/6 dB branch line coupler.

Design Procedure and Fabrication of Reproducible Silicon Vernier Devices for High-Performance Refractive Index Sensing.

In this paper, we propose a generalized procedure for the design of integrated Vernier devices for high performance chemical and biochemical sensing. In particular, we demonstrate the accurate control of the most critical design and fabrication parameters of silicon-on-insulator cascade-coupled racetrack resonators operating in the second regime of the Vernier effect, around 1.55 μm. The experimental implementation of our design strategies has allowed a rigorous and reliable investigation of the influence of racetrack resonator and directional coupler dimensions as well as of waveguide process variability on the operation of Vernier devices. Figures of merit of our Vernier architectures have been measured experimentally, evidencing a high reproducibility and a very good agreement with the theoretical predictions, as also confirmed by relative errors even lower than 1%. Finally, a Vernier gain as high as 30.3, average insertion loss of 2.1 dB and extinction ratio up to 30 dB have been achieved.

Improving isolation of slot‐coupled directional couplers

A suitable method is introduced to improve the isolation of slot-coupled directional couplers. The proposed coupler consists of two trapezoidal-shaped patches that are coupled through a trapezoidal-shaped slot in a common ground plane. The inherent phase velocity differences between the even- and odd-modes of the slot-coupled directional coupler are compensated around the centre frequency of the coupler by introducing some slots to the trapezoidal-shaped patches. A design graph is derived by sweeping some dimensions of the coupler. A hatched area is also added to the design graph that indicates the appropriate coupler dimensions which lead to the equal even- and odd-mode phase velocities around the centre frequency. To demonstrate the effectiveness of the proposed coupler, an 8 dB coupler operating from 1 to 3.3 GHz is designed and constructed. The measurement results are in good agreement with the simulation results. The results show that the isolation of the designed coupler has improved significantly in comparison with the other designed coupler with no cut slots in the patches.

A method for optimal path synthesis of four-link planar mechanisms

The paper deals with the optimal synthesis of planar mechanisms as path generators. The formulation of the synthesis problem enables decreasing the number of design parameters. The angular position of the floating link (coupling link) connecting input and output links is described by function sine. The coupler link is treated as a free body which generates precisely desired motion. The objective is to determine the coupler dimensions for which the coupler joints approximate with a prescribed accuracy the trajectories which these joints trace in the assembled mechanism. The structural error for most typical kinematic pairs was derived in order to apply the method to a wide spectrum of four-link planar mechanisms. Compared with classical path synthesis approach, this technique measures the deviation of the paths of the coupler joints from their paths in the assembled mechanisms, not the deviation of the coupler path from the prescribed trajectory. Various modifications of the method were discussed to widen the range of possible applications. The problem was formulated as an optimization task. An objective function was constructed and minimized in searching for generators of desired motion using an evolutionary algorithm. Test paths were chosen to verify the effectiveness of the method. Numerical tests addressed also practical linkage applications. The technique was verified in the synthesis of four-bar linkage, crank-slider mechanism and mechanism with slotted link. The method was also applied to solve chosen motion synthesis tasks combining the positions and angular orientations of the link.

Thermal and Structural Analysis of Co-axial Coupler used in High Power Helix Traveling-Wave Tube

In traveling-wave tubes (TWTs), coaxial couplers or window assemblies are used for coupling milliwatt (mW) to hundreds of watts of average power. For the proper transformation of impedance of interaction structure to the standard connector, coaxial couplers are suitably modeled as multi-section coaxial transformer. Due to high average power propagation, center conductor of coupler gets heated and the dimensions of multi-section coupler get deformed from its cold condition which causes impedance mismatch and increase of thermal load. Due to impedance mismatch, reflection of RF signal occurs from the couplers causing oscillation and finally leads of destruction of the TWT. This paper presents the thermal and structural analysis of coaxial coupler to quantify the temperature distribution at different regions, deformation of cold dimensions and stress due to material property of window disc.

Tapered Velocity Mode-Selective Couplers

In this paper tapered velocity mode-selective couplers are presented. These tapered couplers are approximately adiabatic devices which unlike standard mode-selective couplers, do not rely on precise phase conditions to be satisfied over an extended length, to achieve their mode-selective functionality. Therefore these mode couplers permit ultra-wideband mode-division multiplexing of few-mode waveguides. Moreover, their behavior is largely independent of parameters such as index contrast and the precise coupler dimensions. The mode-selective functionality is demonstrated in slab geometry, with the principles generalizing to planar or fiber-based devices.

Coupler design for an L-band electron linac

The RF coupler is a key component for an accelerating structure which is the most important component for a linac. In order to feed microwave power into the accelerating cavities effectively, the coupler has to be well matched with the feeding waveguide. In this paper, an electron linac coupler was designed, constructed and tested. A numerical simulation method based on the Kyhl's method was employed to search for the optimal dimensions of the coupler. The frequency and the coupling coefficient as a function of the coupler dimensions were also calculated. The results fitted the Kyhl's method simulation results well and gave tolerances of the coupler. The coupler was brazed to the accelerating cavities and it was cold-tested and hot-tested. The experimental results were consistent with the numerical simulation results.

Semicompliant Force Generator Mechanism Design for a Required Impact and Contact Forces

A novel design of compliant slider-crank mechanism is introduced and utilized as an impact and contact-force generator. This class of compliant slider mechanisms incorporates an elastic coupler, which is an initially straight flexible beam and buckles when it hits the stopper. The elastic pin-pin coupler, a buckling beam, behaves as a rigid body prior to the impact pushing the rigid slider. At a certain crank angle, the slider hits a stopper generating an impact force. This force can be changed by regulating the angular velocity of the crank and by achieving a desired velocity of the slider. Moreover, after the impact when the slider establishes a permanent contact with the stopper, the maximum contact force can also be adjusted by calculating the coupler dimensions (the length, the width, the thickness, and the amount of compression). The contact duration, the crank angular rotation range, can also be changed and attuned in this mechanism by moving the location of the impacted object. Several mechanism designs with the same working principle are introduced. A prototype compliant slider-crank mechanism is constructed and proved the conceptual contributions of the mechanism.

Evaluation of external Q of the superconducting cavity using Kroll-Yu method

Design and development of superconducting (SC) cavity having βg>0.42 has been taken up as a part of the accelerator driven subcritical system project. An input coupler is designed for the SC, elliptical cavity operating at 1.056GHz, using the Kroll-Yu method. The evaluation procedure is optimized and the method has been successfully implemented for the evaluation of high Q external. The effect of beam pipe radius, coupler dimensions, penetration depth, and the position of the coupler on the external Q has also been studied.

A simple procedure for impedance matching and tuning of microwave couplers for an electron linear accelerator

A simple experimental procedure to match and tune "door-knob"-type microwave couplers is presented in this paper. The procedure is suitable for accelerating structures with both input and output couplers and allows a fast convergence to the minimum reflection condition for a cavity coupler with fixed phase shift. The standing-wave ratio and the coupling cavity phase shift as functions of the coupler dimensions and frequency are also reported.

High-Q HF microelectromechanical filters

IC-compatible microelectromechanical intermediate frequency filters using integrated resonators with Q's in the thousands to achieve filter Q's in the hundreds have been demonstrated using a polysilicon surface micromachining technology. These filters are composed of two clamped-clamped beam micromechanical resonators coupled by a soft flexural-mode mechanical spring. The center frequency of a given filter is determined by the resonance frequency of the constituent resonators, while the bandwidth is determined by the coupling spring dimensions and its location between the resonators. Quarter-wavelength coupling is required on this microscale to alleviate mass loading effects caused by similar resonator and coupler dimensions. Despite constraints arising from quarter-wavelength design, a range of percent bandwidths is still attainable by taking advantage of low-velocity spring attachment locations. A complete design procedure is presented in which electromechanical analogies are used to model the mechanical device via equivalent electrical circuits. Filter center frequencies around 8 MHz with Q's from 40 to 450 (i.e., percent bandwidths from 0.23 to 2.5%), associated insertion losses less than 2 dB, and spurious-free dynamic ranges around 78 dB are demonstrated using low-velocity designs with input and output termination resistances of the order of 12 k/spl Omega/.

Matching of quasioptical open resonators with waveguide feeders

We consider a semisymmetric open resonator (OR) included in a waveguide feeder, in which the first higher-order mode is excited. We show that a high efficiency of excitation of the mode can be achieved by appropriate choice of coupler dimensions due to the matching of structures of the exciting and operating fields.