scholarly journals Chebyshev-Response Branch-Line Couplers with Enhanced Bandwidth and Arbitrary Coupling Level

Electronics ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 1828
Author(s):  
Robert Smolarz ◽  
Krzysztof Wincza ◽  
Slawomir Gruszczynski
Keyword(s):  
Chebyshev Polynomial ◽  
Coupling Coefficient ◽  
Center Frequency ◽  
Electrical Parameters ◽  
New Approach ◽  
Branch Line ◽  
Design Procedures ◽  
Arbitrary Coupling

A new approach to the synthesis of broadband branch-line couplers with arbitrary coupling level was investigated in this paper. It was shown that the operational bandwidth of a classic branch-line coupler can be increased by utilizing N-section impedance transformers added to each of the coupler’s ports. Furthermore, the obtained response can be approximated by the Chebyshev polynomial. Moreover, it was proven that for such couplers a range of coupling coefficient values can be obtained by the modification of classic branch-line topology. The analysis of the electrical parameters of the proposed branch-line couplers was comprehensively investigated. To verify the correctness of the proposed design procedures, 3-dB, and 6-dB broadband branch-line couplers operating at the center frequency of 2 GHz having return losses greater than 20 dB were designed, fabricated, and measured.

scholarly journals GENERALIZED IMPEDANCE-TRANSFORMING DUAL-BAND BRANCH-LINE COUPLERS FOR ARBITRARY COUPLING LEVELS

2013 ◽  
Vol 53 ◽  
pp. 399-415 ◽  
Author(s):  
Qiang Liu ◽  
Yuanan Liu ◽  
Yongle Wu ◽  
Jun-Yu Shen ◽  
Shulan Li ◽  
...  
Keyword(s):  
Dual Band ◽  
Branch Line ◽  
Arbitrary Coupling

Novel rat-race coupler design of arbitrary coupling coefficient using substrate integrated waveguide cavity

2018 ◽  
Vol 10 (8) ◽  
pp. 861-869 ◽  
Author(s):  
Min-Hua Ho ◽  
Yi-Hao Hong ◽  
Jen-Chih Li
Keyword(s):  
Transmission Lines ◽  
Coupling Coefficient ◽  
Substrate Integrated Waveguide ◽  
Cavity Field ◽  
Arbitrary Coupling ◽  
Degenerate Mode ◽  
Quarter Wavelength ◽  
Small Phase ◽  
Hybrid Coupler ◽  
Degenerate Modes

AbstractThe contribution of this paper is to propose a novel rat-race hybrid coupler of arbitrary coupling coefficient. Traditionally, the rat-race hybrid couplers are built by various loop-alike transmission-lines of multiple quarter-wavelength, and in this paper, we approach the coupler design by using a circular substrate integrated waveguide (SIW) cavity (SIWC). The employed SIWC supports two mutually orthogonal degenerate modes, and cavity field is formed by the two modes in an arbitrary weighting ratio which defines the proposed rat-race coupler's coupling coefficient. The cavity is excited by a microstrip combined coupling slot with the microstrip along a specifically chosen direction. The energy of each degenerate mode can be solely extracted by an associated subminiature version A (SMA) whose position is carefully determined. The isolation between the coupling slots is assured by their perpendicular layout, and the isolation between the SMA probes is obtained by the orthogonality of the two degenerate modes. Experiments are conducted on the 3- and 10-dB coupling coefficient samples to verify this novel rat-race coupler design. The measurements agree well with the simulations, and circuit's good performance is observed in terms of coupling precision, isolations, and small phase imbalances.

scholarly journals Design of Sectoral Antennas Using a Metallic EBG Structure and Multiple Sources Feeding for Base Station Applications

2008 ◽  
Vol 2008 ◽  
pp. 1-6 ◽  
Author(s):  
M. Hajj ◽  
E. Rodes ◽  
D. Serhal ◽  
T. Monédière ◽  
B. Jecko
Keyword(s):  
Band Gap ◽  
Radiation Pattern ◽  
Base Station ◽  
Printed Antenna ◽  
Multiple Sources ◽  
Metallic Structures ◽  
Electromagnetic Band Gap ◽  
New Approach ◽  
Design Procedures ◽  
Base Station Antennas

This work aims to study and design base station antennas with metallic electromagnetic band gap (EBG) materials able to create a sectoral radiation pattern presenting at least a beamwidth. The use of metallic structures offers a new approach to industrial partners seeking to reduce costs and facilitate design procedures. A new method allowing the improvement of both the directivity and the bandwidth by using a printed antenna array is studied.

scholarly journals Analysis and Introduction of Effective Permeability with Additional Air-Gaps on Wireless Power Transfer Coils for Electric Vehicle Based on SAE J2954 Recommended Practice

Energies ◽  
2019 ◽  
Vol 12 (24) ◽  
pp. 4797 ◽  
Author(s):  
Dongwook Kim ◽  
Hongseok Kim ◽  
Anfeng Huang ◽  
Qiusen He ◽  
Hanyu Zhang ◽  
...  
Keyword(s):  
Coupling Coefficient ◽  
Effective Permeability ◽  
Impedance Matching ◽  
Wireless Power Transfer ◽  
The Self ◽  
Power Transfer ◽  
Wireless Power ◽  
Electrical Parameters ◽  
Testing Procedures ◽  
Receiving Coil

The wireless power transfer (WPT) method for electric vehicles (EVs) is becoming more popular, and to ensure the interoperability of WPT systems, the Society of Automotive Engineers (SAE) established the J2954 recommended practice (RP). It includes powering frequency, electrical parameters, specifications, testing procedures, and other contents for EV WPT. Specifically, it describes the ranges of self-inductances of the transmitting coil, the receiving coil, and coupling coefficient (k), as well as the impedance matching values of the WPT system. Following the electrical parameters listed in SAE J2954 RP is crucial to ensure the EV wireless charging system is interoperable. This paper introduces a method for adjusting the effective permeability of the ferrite blocks in the standard model, to tune the self-inductance of the coils as well as the coupling coefficient. To guarantee the given values of the self-inductance of the coil and coupling coefficient matched those in the standard, we slightly modified the air-gap between the ferrite tiles in a specific region. Based on this method, it was possible to successfully tune the self-inductance of the transmitting coil and receiving coil as well as the coupling coefficient. The proposed method was verified by simulation and experimental measurements.

Estimating Number of Shells in Shell and Tube Heat Exchangers: A New Approach Based on Temperature Cross

2000 ◽  
Vol 122 (3) ◽  
pp. 566-571 ◽  
Author(s):  
B. B. Gulyani
Keyword(s):  
Correction Factor ◽  
Heat Exchangers ◽  
Present Formulation ◽  
New Approach ◽  
Design Procedures ◽  
Rule Of Thumb ◽  
S Parameter ◽  
Limited Temperature ◽  
Shell And Tube

Multipass heat exchangers are often designed by using the rule of thumb FT⩾0.75, which is rather arbitrary. FT falls sharply with the increase in temperature cross. Hence, only a limited temperature cross can be allowed. The ability to accommodate temperature cross increases rapidly as the number of shell passes is increased. Though many investigators have emphasized the importance of temperature cross in exchanger design, it has as yet not been explicitly accounted for in the design. This paper introduces a new approach for estimating the number shells in a shell and tube exchanger which directly accounts for temperature cross, rather than routing this effect through FT or XP (Ahmad et al.’s parameter, which is again a correction factor not directly related to temperature cross). The approach is compatible with the established design procedures and bypasses the FT. It generates better designs by defining maximum permissible temperature cross, than the traditional designs based on specifying minimum permissible FT. Expressions have also been provided which correlate the present formulation with that of Ahmad et al. [S0022-1481(00)00803-3]

Type synthesis of legged mobile landers with one passive limb using the singularity property

Robotica ◽  
2018 ◽  
Vol 36 (12) ◽  
pp. 1836-1856 ◽  
Author(s):  
Rongfu Lin ◽  
Weizhong Guo ◽  
Xianbao Chen ◽  
Meng Li
Keyword(s):  
Autonomous Robots ◽  
The Novel ◽  
Legged Robot ◽  
Type Synthesis ◽  
Typical Structure ◽  
New Approach ◽  
Lie Group Theory ◽  
Software Simulation ◽  
Design Procedures ◽  
Novel Structures

SUMMARYDuring extraterrestrial planetary exploration programs, autonomous robots are deployed using a separate immovable lander and a rover. This mode has some limitations. In this paper, a concept of a novel legged robot with one passive limb and singularity property is introduced that has inbuilt features of a lander and a rover. Currently, studies have focused primarily on a performance analysis of the lander without a walking function. However, a systematic type synthesis of the legged mobile lander has not been studied. In this study, a new approach to the type synthesis used for the robot is proposed based on the Lie group theory. The overall concept and design procedures are proposed and described. The motion requirements of the robot and its legs, which are corresponding to the multi-function, are extracted and described. The layouts of the subgroups or submanifolds of the limbs are determined. The structures of the passive and actuated limbs are synthesized. Numerous structures of the legs with a passive limb are produced and listed corresponding to the desired displacement manifolds. Numerous novel structures of legs for the legged mobile lander are presented and listed. Then, four qualitative criteria or indexes are introduced. Based on the proposed criteria, a leg's configuration is selected as the best. A typical structure of the legged mobile lander is obtained by assembling the structures of the proposed legs. Finally, the typical robot is used as an example to verify the capabilities of the novel robot using a software simulation (ADAMS).

scholarly journals Microstrip Triband Bandstop Fitler with Sharp Stop Band Skirts and Independently Controllable Second Stop Band Response

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Kishor Kumar Adhikari ◽  
Nam-Young Kim
Keyword(s):  
High Selectivity ◽  
Design Method ◽  
Stop Band ◽  
Center Frequency ◽  
Pass Band ◽  
Analysis And Design ◽  
Design Procedures ◽  
Compact Size ◽  
And Control ◽  
Compact Planar

This paper presents a compact planar triband bandstop filter (TBBSF) with compact size and high selectivity. The structure of the filter incorporates two folded trisection stepped-impedance resonators (TSSIRs). One of these resonators is designed to operate at the first and third center frequencies and the other resonator is designed to operate at the second center frequency of the proposed filter. To achieve a compact size filter, alternating impedance lines of the resonators are folded widthwise and also one resonator is embedded within another. Theoretical analysis and design procedures are described, including the synthesis equations for each resonator. The main advantage of the proposed method is that the filter provides flexibility to tune the second center frequency and control the corresponding bandwidth without changing the first and third stop band response. Additionally, several reflection zeros (RZs) are introduced in the pass band to improve its flatness. To demonstrate the feasibility of the proposed design method, both the first and second order TBBSFs were designed, simulated, and fabricated, with center frequencies of 1.92 GHz, 3.55 GHz, and 5.5 GHz.

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