Forbidden regions of L-section impedance matching networks on Meta-Smith charts for conjugately characteristic-impedance transmission lines

2015 ◽  
Vol 57 (4) ◽  
pp. 874-879
Author(s):  
Danai Torrungrueng ◽  
Theeraputh Mekathikom
Keyword(s):  
Transmission Lines ◽  
Impedance Matching ◽  
Characteristic Impedance ◽  
Matching Networks ◽  
Forbidden Regions

scholarly journals Series-connected array of superconductor–insulator–superconductor junctions in the 100 GHz-band heterodyne mixer for FOREST on the Nobeyama 45 m telescope

2018 ◽  
Vol 71 (Supplement_1) ◽  
Author(s):  
Taku Nakajima ◽  
Hirofumi Inoue ◽  
Yumi Fujii ◽  
Chieko Miyazawa ◽  
Hiroyuki Iwashita ◽  
...  
Keyword(s):  
Transmission Lines ◽  
Quartz Substrate ◽  
Impedance Matching ◽  
Characteristic Impedance ◽  
Noise Temperature ◽  
Coupling Efficiency ◽  
Wide Frequency Range ◽  
Quantum Limit ◽  
Receiver Noise ◽  
Sis Junction

Abstract We have designed and experimentally evaluated a series-connected array of superconductor–insulator–superconductor (SIS) junctions in the 100 GHz-band mixer for the multi-beam receiver FOREST on the Nobeyama 45 m millimeter-wave telescope. The construction of the junction chip comprised a waveguide probe antenna, impedance-matching circuit, SIS array junction, and choke filter, which were made from a superconducting niobium planar circuit on a quartz substrate. The multi-stage impedance-matching circuit between the feed point and the SIS junction was designed as a capacitively loaded transmission line, and it comprised two sections with high (∼90 Ω) and low (∼10 Ω) characteristic impedance transmission lines. The structure of this tuning line was simple and easy to fabricate, and the feed impedance matched with the SIS junction in a wide frequency range. The signal coupling efficiency was more than 92% and the expected receiver noise temperature was approximately twice the quantum limit for 75–125 GHz based on quantum theory. The array junction devices with three to six connected junctions were fabricated and we measured their performance in terms of the receiver noise temperature and gain compression in the laboratory. We successfully developed an array junction device with a receiver noise temperature of ∼15–30 K and confirmed that the improvement in the saturation power corresponded to the number of junctions. The newly developed array junction mixer was installed in the FOREST receiver and it successfully detected the 12CO(J = 1–0) molecular line toward IRC +10216 with the Nobeyama 45 m telescope.

scholarly journals On the Design of Broadband Hybrid Amplifiers Using Non-Uniform Transmission Lines as Impedance Matching Networks

IEEE Access ◽  
2019 ◽  
Vol 7 ◽  
pp. 19670-19677 ◽  
Author(s):  
Miguel Fernandez ◽  
Samuel Ver Hoeye ◽  
Carlos Vazquez ◽  
Leticia Alonso Gonzalez ◽  
Fernando Las-Heras
Keyword(s):  
Transmission Lines ◽  
Impedance Matching ◽  
Matching Networks

scholarly journals Optimum power transfer in RF front end systems using adaptive impedance matching technique

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Mohammad Alibakhshikenari ◽  
Bal S. Virdee ◽  
Leyre Azpilicueta ◽  
Chan H. See ◽  
Raed Abd-Alhameed ◽  
...  
Keyword(s):  
Impedance Matching ◽  
Adaptive Antenna ◽  
Power Transfer ◽  
Control Loops ◽  
Matching Networks ◽  
Front End ◽  
Rf Front End ◽  
Matching Technique ◽  
Digital Circuitry ◽  
Communications System

AbstractMatching the antenna’s impedance to the RF-front-end of a wireless communications system is challenging as the impedance varies with its surround environment. Autonomously matching the antenna to the RF-front-end is therefore essential to optimize power transfer and thereby maintain the antenna’s radiation efficiency. This paper presents a theoretical technique for automatically tuning an LC impedance matching network that compensates antenna mismatch presented to the RF-front-end. The proposed technique converges to a matching point without the need of complex mathematical modelling of the system comprising of non-linear control elements. Digital circuitry is used to implement the required matching circuit. Reliable convergence is achieved within the tuning range of the LC-network using control-loops that can independently control the LC impedance. An algorithm based on the proposed technique was used to verify its effectiveness with various antenna loads. Mismatch error of the technique is less than 0.2%. The technique enables speedy convergence (< 5 µs) and is highly accurate for autonomous adaptive antenna matching networks.

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.

scholarly journals Overcoming the Realization Problems of Wideband Matching Circuits

2018 ◽  
pp. 31-36
Author(s):  
Balázs Matolcsy ◽  
Attila Zólomy
Keyword(s):  
Design Process ◽  
Circuit Simulation ◽  
Impedance Matching ◽  
Microwave Circuit ◽  
Design Rules ◽  
Analytical Design ◽  
Calculation Technique ◽  
Matching Networks ◽  
Practical Design

During the analytical design process of wideband impedance matching major problems may arise, that might lead to non-realizable matching networks, preventing the successful impedance matching. In this paper two practical design rules and a simplified equation is presented, supporting the design of physically realizable impedance matching networks. The design rules and calculation technique introduced by this paper is summarized, and validated by microwave circuit simulation examples.

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.

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