A NEW CALCULATION METHOD FOR THE CHARACTERISTIC IMPEDANCE OF TRANSMISSION LINES WITH MODIFIED GROUND STRUCTURES OR PERTURBATION

The effect of loss of transmission line on the transmission signal can’t be ignored in microwave circuits. Based on the theory of loss and microwave network principle, the effect of the width, parallel length and space of transmission lines on the scattering parameters’ insertion loss is analyzed in perspective of scattering parameters of the odd mode and even mode. The simulation results show that: when the other parameters are fixed, both the characteristic impedance and the conductor loss decrease non-linearly with the line width broadening; due to the coupling effect between micro-strip lines, the first trough frequency of the scattering parameter S21 curved line, that is the point the signal energy attenuate most seriously, decreases linearly with line width broadening and increases non- linearly with line spaces broadening.

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A Novel Synthetization Approach for Multi Coupled Line Section Impedance Transformers in Wideband Applications

Applied Sciences ◽

10.3390/app12020875 ◽

2022 ◽

Vol 12 (2) ◽

pp. 875

Author(s):

Nan Zhang ◽

Xiaolong Wang ◽

Chunxi Bao ◽

Bin Wu ◽

Chun-Ping Chen ◽

...

Keyword(s):

Transmission Lines ◽

Return Loss ◽

Circuit Simulation ◽

Characteristic Impedance ◽

Fractional Bandwidth ◽

Coupled Line ◽

Variable Parameters ◽

Line Section ◽

Original Topology ◽

Impedance Parameters

In this paper, a novel synthetization approach is proposed for filter-integrated wideband impedance transformers (ITs). The original topology consists of N cascaded coupled line sections (CLSs) with 2N characteristic impedance parameters. By analyzing these characteristic impedances, a Chebyshev response can be derived to consume N + 2 design conditions. To optimize the left N − 2 variable parameters, CLSs were newly substituted by transmission lines (TLs) to consume the remaining variable parameters and simplify the circuit topology. Therefore, there are totally 2N − N − 2 substituting possibilities. To verify the proposed approach, 25 cases are listed under the condition of N = 5, and 7 selected cases are compared and discussed in detail. Finally, a 75–50 Ω IT with 100% fractional bandwidth and 20 dB bandpass return loss (RL) is designed and fabricated. The measured results meet the circuit simulation and the EM simulation accurately.

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Transient Temperature Calculation and Multi-Parameter Thermal Protection of Overhead Transmission Lines Based on an Equivalent Thermal Network

Energies ◽

10.3390/en12010067 ◽

2018 ◽

Vol 12 (1) ◽

pp. 67 ◽

Cited By ~ 3

Author(s):

Jian Hu ◽

Xiaofu Xiong ◽

Jing Chen ◽

Wei Wang ◽

Jian Wang

Keyword(s):

Power System ◽

Transmission Line ◽

Transmission Lines ◽

Calculation Method ◽

Thermal Protection ◽

Transient Temperature ◽

Accurate Analysis ◽

Temperature Calculation ◽

Overhead Transmission Lines ◽

Thermal Network

The overload degree of a transmission line is represented by currents in traditional overload protection, which cannot reflect its safety condition accurately. The sudden rise in transmission line current may lead to cascading tripping under traditional protection during power flow transfer in a power system. Therefore, timely and accurate analysis of the transient temperature rise of overhead transmission lines, revealing their overload endurance capability under the premise of ensuring safety, and coordination with power system controls can effectively eliminate overloading. This paper presents a transient temperature calculation method for overhead transmission lines based on an equivalent thermal network. This method can fully consider the temperature-dependent characteristics with material properties, convective heat resistance, and radiation heat and can accurately calculate the gradient distribution and response of the conductor cross-section temperature. The validity and accuracy of the proposed calculation method are verified by a test platform. In addition, a multi-parameter thermal protection strategy is proposed on the basis of the abovementioned calculation method. The protection can adequately explore the maximum overload capability of the line, and prevent from unnecessary tripping to avoid the expansion of accidents. Finally, the validity of the proposed protection is verified by the modified 29-bus system.

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Transmission Line

Practical Approach to Substrate Integrated Waveguide (SIW) Diplexer - Advances in Mechatronics and Mechanical Engineering ◽

10.4018/978-1-7998-2084-0.ch002 ◽

2020 ◽

pp. 43-71

Keyword(s):

Transmission Line ◽

Transmission Lines ◽

Magnetic Energy ◽

Propagation Constant ◽

Characteristic Impedance ◽

Electric Energy ◽

Electromagnetic Energy ◽

The Other ◽

Electrical Characteristics ◽

Lumped Elements

A transmission line (TL) is simply a medium that is capable of guiding or propagating electromagnetic energy. The transmission line stores the electric (E) and magnetic (M) energies and distributes them in space by alternating them between the two forms. This means that at any point along a TL, energy is stored in a mixture of E and M forms and, for an alternating signal at any point on the TL, converted from one form to the other as time progresses. Transmission line is usually modelled using lumped elements (i.e., inductors for magnetic energy, capacitors for electric energy, and resistors for modelling losses). The electrical characteristics of a TL such as the propagation constant, the attenuation constant, the characteristic impedance, and the distributed circuit parameters can only be determined from the knowledge of the fields surrounding the transmission line. This chapter gives a brief overview of various transmission lines, with more detailed discussions on the microstrip and the SIW.

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Solving the Complexity Problem in the Electronics Production Process by Reducing the Sensitivity of Transmission Line Characteristics to Their Parameter Variations

Complexity ◽

10.1155/2019/6301326 ◽

2019 ◽

Vol 2019 ◽

pp. 1-11 ◽

Cited By ~ 2

Author(s):

Talgat R. Gazizov ◽

Indira Ye. Sagiyeva ◽

Sergey P. Kuksenko

Keyword(s):

Transmission Line ◽

Production Process ◽

Transmission Lines ◽

Unit Length ◽

Characteristic Impedance ◽

Optimal Choice ◽

Wide Range ◽

Complexity Problem ◽

Parameter Variations ◽

Parameter Values

In this paper we consider the complexity problem in electronics production process. Particularly, we investigate the ways to reduce sensitivity of transmission line characteristics to their parameter variations. The reduction is shown for the per-unit-length delay and characteristic impedance of several modifications of microstrip transmission lines. It can be obtained by means of making an optimal choice of parameter values, enabling proper electric field redistribution in the air and the substrate. To achieve this aim we used an effective simulation technique and software tools. Taken together, for the first time, they have allowed formulating general approach which is relevant to solve a wide range of similar tasks.

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