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

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.

scholarly journals A Novel Analytical Design Technique for a Wideband Wilkinson Power Divider Using Dual-Band Topology

Sensors ◽  
2021 ◽  
Vol 21 (19) ◽  
pp. 6330
Author(s):  
Asif I. Omi ◽  
Rakibul Islam ◽  
Mohammad A. Maktoomi ◽  
Christine Zakzewski ◽  
Praveen Sekhar
Keyword(s):  
Transmission Lines ◽  
Return Loss ◽  
Power Divider ◽  
Dual Band ◽  
Design Technique ◽  
Fractional Bandwidth ◽  
Coupled Line ◽  
Analytical Design ◽  
Resonance Frequencies ◽  
Wilkinson Power Divider

In this paper, a novel analytical design technique is presented to implement a coupled-line wideband Wilkinson power divider (WPD). The configuration of the WPD is comprised of three distinct coupled-line and three isolation resistors. A comprehensive theoretical analysis is conducted to arrive at a set of completely new and rigorous design equations utilizing the dual-band behavior of commensurate transmission lines. Further, the corresponding S-parameters equations are also derived, which determine the wideband capability of the proposed WPD. To validate the proposed design concept, a prototype working at the resonance frequencies of 0.9 GHz and 1.8 GHz is designed and fabricated using 60 mils thick Rogers’ RO4003C substrate. The measured result of the fabricated prototype exhibits an excellent input return loss > 16.4 dB, output return loss > 15 dB, insertion loss < 3.30 dB and a remarkable isolation > 22 dB within the band and with a 15 dB and 10 dB references provide a fractional bandwidth of 110% and 141%, respectively.

A multi-mode resonator-based UWB bandpass filter with wide stopband

2015 ◽  
Vol 8 (7) ◽  
pp. 1031-1035 ◽  
Author(s):  
Ting Zhang ◽  
Fei Xiao ◽  
Xiaohong Tang ◽  
Lei Guo
Keyword(s):  
Return Loss ◽  
Bandpass Filter ◽  
Mode Analysis ◽  
Frequency Range ◽  
Coupled Line ◽  
Resonance Characteristic ◽  
Line Section ◽  
Multi Mode ◽  
Mode Resonator ◽  
Better Than

In this paper, a novel multi-mode resonator is presented, which is formed by cascading several open-circuited transmission line sections with a coupled-line section. Owing to its symmetry, even- and odd-mode analysis methods are applied to analyze its resonance characteristic. Based on this resonator, a microstrip ultra-wide bandwidth (UWB) bandpass filter is designed, fabricated, and measured. The simulated and measured results show that its bandwidth can cover the desired UWB. Return loss in passband is better than −14 dB. This filter is featured by good selectivity and wide stopband. Stopband suppression as low as −40 dB can be achieved within frequency range from 12 to 16 GHz.

scholarly journals Novel Low-Cost Power Divider for 5.8 GHz

Electronics ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 699
Author(s):  
Tso-Jung Chang ◽  
Krishna Pande ◽  
Heng-Tung Hsu
Keyword(s):  
Transmission Lines ◽  
Insertion Loss ◽  
Printed Circuit Board ◽  
Characteristic Impedance ◽  
Past Research ◽  
Size Reduction ◽  
Circuit Board ◽  
Superior Performance ◽  
Published Data ◽  
Coupled Line

This paper presents a new capacitive lump-free structure for power dividers using a printed-circuit board, while maintaining size reduction and physical isolation. The conventional lumped capacitors approach has self-resonant problem and cause worse S 22 and isolation at high frequencies. To overcome such technical issues, the coupled-line structures were introduced in the isolation network. After optimizing the distance between output ports and position of the isolation network, tuning the characteristic impedance and electrical length of transmission lines can decide the value of the lump resistor. The first example was designed at 1 GHz, and the resistor in the isolation network was 330 ohm, having 0.2-dB insertion loss and 19% total bandwidth, while maintaining 80-degree distance between split ports and 180-degree total length, providing 21% to 67% size reduction. The second example was designed at 5.8 GHz, which was five times greater than in past research, using an RO4003C substrate while maintaining a 0.24-dB insertion loss, 17% total bandwidth, and 0.06 dB amplitude imbalance, which was only 0.01 dB more than in recent research. Such superior performance is mainly attributed to the coupled transmission lines in the isolation network featuring a capacitive lump-free isolation network. Our data indicate that amplitude imbalance, bandwidth, and miniaturization are superior to any published data.

scholarly journals Highly Sensitive Reflective-Mode Defect Detectors and Dielectric Constant Sensors Based on Open-Ended Stepped-Impedance Transmission Lines

Sensors ◽  
2020 ◽  
Vol 20 (21) ◽  
pp. 6236
Author(s):  
Pau Casacuberta ◽  
Jonathan Muñoz-Enano ◽  
Paris Vélez ◽  
Lijuan Su ◽  
Marta Gil ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Transmission Line ◽  
Transmission Lines ◽  
Characteristic Impedance ◽  
Reference Sample ◽  
Phase Variation ◽  
Dielectric Constants ◽  
High Impedance ◽  
Line Section ◽  
Highly Sensitive

In this paper, reflective-mode phase-variation sensors based on open-ended stepped-impedance transmission lines with optimized sensitivity for their use as defect detectors and dielectric constant sensors are reported. The sensitive part of the sensors consists of either a 90° high-impedance or a 180° low-impedance open-ended sensing line. To optimize the sensitivity, such a sensing line is cascaded to a 90° transmission line section with either low or high characteristic impedance, resulting in a stepped-impedance transmission line configuration. For validation purposes, two different sensors are designed and fabricated. One of the sensors is implemented by means of a 90° high impedance (85 Ω) open-ended sensing line cascaded to a 90° low impedance (15 Ω) transmission line section. The other sensor consists of a 180° 15-Ω open-ended sensing line cascaded to a 90° 85-Ω line. Sensitivity optimization for the measurement of dielectric constants in the vicinity of that corresponding to the Rogers RO4003C substrate (i.e., with dielectric constant 3.55) is carried out. The functionality as a defect detector is demonstrated by measuring the phase-variation in samples consisting of the uncoated Rogers RO4003C substrate (the reference sample) with arrays of holes of different densities.

scholarly journals Compact Two-Section Half-Wave Balun Based on Planar Artificial Transmission Lines

2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
Changjun Liu ◽  
Zhenyu Yin ◽  
Yilan Yang ◽  
Wen Huang
Keyword(s):  
Transmission Line ◽  
Transmission Lines ◽  
Microwave Power ◽  
Parallel Plate ◽  
Return Loss ◽  
Characteristic Impedance ◽  
Size Reduction ◽  
Power Combining ◽  
Half Wave ◽  
Phase Balance

Artificial transmission lines are realized by a series of meandered-line inductors, parallel-plate capacitors, and interdigital capacitors, which belong to metamaterial transmission lines. An ameliorated artificial transmission line is proposed to realize a low characteristic impedance transmission line. A two-section half-wave balun at 900 MHz is designed, fabricated, and measured in this paper. The compact balun is based on conventional and ameliorated planar artificial transmission lines instead of microstrip transmission lines. The main advantage of the proposed balun is its size reduction, which occupies only about 10% of a conventional one. Measured results match well with theory and simulation. The balun features excellent amplitude and phase balance in microwave power combining and a reasonable bandwidth of the return loss as well.

Design of coaxial and waveguide couplers for helix TWT

Frequenz ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Mukesh Kumar Alaria ◽  
Sanjay Kumar Ghosh
Keyword(s):  
Traveling Wave ◽  
Return Loss ◽  
Characteristic Impedance ◽  
Three Dimensional ◽  
Waveguide Coupler ◽  
Quarter Wavelength ◽  
Different Types ◽  
Waveguide Type ◽  
Transformer Design ◽  
Traveling Wave Tubes

Abstract In this paper, two types of coaxial coupler and waveguide coupler for different frequency helix traveling wave tubes (TWTs) are designed, fabricated and cold tested. The coaxial coupler includes of window ceramic and RF transformer section. At present multi-section impedance transformer design approach is used for wideband helix TWTs. In any helix TWT, impedance of the source is transformed to the characteristic impedance of helix. This is done by the quarter-wavelength (λ/4) impedance transformation approach. The simulated results of different types of couplers are carried out by HFSS and CST microwave studio software and compare with experimental results. Three-dimensional electromagnetic field simulators allowing the any geometry with port excitations it is possible to model the complex coaxial and waveguide type couplers with helix SWS assembly and predict its desired return loss performances.

Analysis of Characteristic of Microstrip Signal Loss in Course of Signal Transmission

2011 ◽  
Vol 194-196 ◽  
pp. 2229-2232
Author(s):  
Qing Song Xiong ◽  
Zhao Hua Wu ◽  
Pin Chen ◽  
Sheng Zhang
Keyword(s):  
Line Width ◽  
Transmission Lines ◽  
Coupling Effect ◽  
Signal Transmission ◽  
Characteristic Impedance ◽  
Signal Loss ◽  
Scattering Parameters ◽  
Scattering Parameter ◽  
Conductor Loss ◽  
Strip Lines

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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